AP Biology
Course Description
AP Biology is an introductory college-level biology course. Students cultivate their understanding of biology through inquiry-based investigations as they explore the following topics: evolution, cellular processes, energy and communication, genetics, information transfer, ecology, and interactions
From AP Biology ® Course and Exam Description, Fall 2019
Course Big Ideas
- The process of evolution drives the diversity and unity of life. (EVO)
- Biological systems use energy and molecular building blocks to grow, reproduce, and maintain dynamic homeostasis. (ENE)
- Living systems store, retrieve, transmit, and respond to information essential to life processes. (IST)
- Biological systems interact, and these systems and their interactions exhibit complex properties. (SYI)
From AP Biology ® Course and Exam Description, Fall 2019
Course Essential Questions
- How are scientific experiments designed and analyzed?
- What are the roles of inorganic molecules (especially water) and organic molecules in cells and other biological systems?
- What are the functional components of cells, and how do these structures contribute to the organization of life?
- How do living organisms obtain and use energy to maintain their structural organization?
- What is the role of cellular communication in unicellular populations and in multicellular organisms?
- What is the physical basis of inheritance?
- How can our modern understanding of genetics be used in health and medicine, agriculture, and other avenues for the benefit of humans and for the benefit of other organisms on Earth?
- How do populations change in response to their environment? What evidence is there to support our understanding of such changes?
- How are the interactions within a biological system directly related to the system’s available energy and its ability to respond to changes?
Course Competencies
- Concept Explanation: Students will be able to explain biological concepts, processes, and models presented in written format.
- Visual Representations: Students will be able to analyze visual representations of biological concepts and processes.
- Questions and Methods: Students will be able to determine scientific questions and methods.
- Representing and Describing Data: Students will be able to represent and describe data.
- Statistical Tests and Data Analysis: Students will be able to perform statistical tests and mathematical calculations to analyze and interpret data.
- Argumentation: Students will be able to develop and justify scientific arguments using evidence.
From AP Biology ® Course and Exam Description, Fall 2019
Course Assessments
- Formal and informal laboratory write-ups and teacher observations of labs
- In class activities and homework assignments
- Projects
- Essays
- Teacher-designed summative assessments
- AP-style unit (summative) assessments
- Cumulative midterm and final exams
Course Units
- Unit 1: Intro to Biology, the Scientific Method, & Statistics
- Unit 2: Biochemistry
- Unit 3: Cells & Cell Structure
- Unit 4: Bioenergetics
- Unit 5: Molecular Genetics
- Unit 6: Multicellularity
- Unit 7: Inheritance
- Unit 8: Evolution
- Unit 9: Ecology
Unit 1: Intro to Biology, the Scientific Method, & Statistics
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- SP2: Analyze visual representations of biological concepts and processes.
- SP3: Determine scientific questions and methods.
- SP4: Represent and describe data.
- SP5: Perform statistical tests and mathematical calculations to analyze and interpret data.
- SP6: Develop and justify scientific arguments using evidence.
AP Biology Course Content Standards
- SYI-1: Living systems are organized in a hierarchy of structural levels that interact.
- EVO-1: Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence.
- EVO-2: Organisms are linked by lines of descent from common ancestry.
PA Reading and Writing in Science and Technical Subjects
CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
- Levels of biological organization, from atoms to biosphere.
- Definition of emergent properties and relevant examples.
- Overview of cellular structures; in particular, the structures common in all cells and those that differ between prokaryotic and eukaryotic cells.
- Overarching themes of biology, including gene expression, heredity, interactions of organisms, and the role of evolution in the diversity and unity of life.
- Parts of a controlled experiment, including independent and dependent variables, controlled variables, and positive and negative controls.
- SI units and metric system.
- Types of data that can be directly measured, and how to manipulate those data.
- Statistical tests for comparing two sets of data.
- Statistical tests for determining a relationship between two variables.
- Importance of error and confidence in data.
- Parts of a graph that can communicate information.
- Parts of a table that can communicate information.
Understanding/Key Learning
- Biology can be studied at many “levels,” including the chemical, cellular, organismal, and ecological levels. These levels have emergent properties that a reductionist view does not properly account for.
- All life on Earth can be classified based on cell types and evolutionary histories.
- Scientific investigations and observational studies are used to collect data that can help support or refute null and alternative hypotheses.
- Data are analyzed using statistical methods to determine what, if any, relationship exists between two variables.
- Graphs are methods of communicating the most important, distilled data.
Do
- Use phylogenetic trees and cladograms to infer evolutionary histories and evolutionary relationships.
- Represent relationships within biological models, including mathematical models, diagrams, and/or flow charts.
- Identify or pose a testable question based on an observation, data, or a model.
- State the null or alternative hypotheses, and/or predict the results of an experiment.
- Identify experimental procedures that are aligned to the question, including identifying dependent and independent variables, identifying appropriate controls, and justifying appropriate controls.
- Make observations, or collect data from representations of laboratory setups or results.
- Propose a new/next investigation based on an evaluation of the evidence from an experiment; and an evaluation of the design/methods.
- Construct a graph, plot, or chart (X,Y; Log Y; Bar; Histogram; Line, Dual Y; Box and Whisker; Pie) with respect to orientation, labeling, units, scaling, plotting, type, and trend line.
- Describe data from a table or graph, including identifying specific data points, describing trends and/or patterns in the data, and describing relationships between variables.
- Perform mathematical calculations, including mathematical equations in the curriculum, means, rates, ratios, and percentages.
- Use confidence intervals and/or error bars (both determined using standard errors) to determine whether sample means are statistically different.
- Perform chi-square hypothesis testing.
- Use data to evaluate a hypothesis (or prediction), including rejecting or failing to reject the null hypothesis and supporting or refuting the alternative hypothesis.
- Use Excel, Numbers, or Sheets to calculate means, standard deviation, standard errors, p-values, and other statistical calculations.
Unit Essential Questions
Lesson Essential Questions
- How is biology studied at various levels of organization and complexity?
- How does evolution help explain the similarities and differences between all living things?
- How are scientific hypotheses developed and tested?
- How are data collected and described?
- How can data be manipulated to make it useful?
- How are data best displayed?
- How are data used to support or disprove hypotheses?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- HHMI: Finches of the Galapagos
- Google Sheets / Mac Numbers / Microsoft Excel
- Other relevant materials and online resources, as needed
Vocabulary
- Abiotic
- Deductive Reasoning
- Manipulated Data
- Qualitative Data
- Adaptation
- Degrees Of Freedom
- Mean
- Quantitative Data
- Animal
- Dependent Variable
- Median
- Range
- Archaea
- Discrete Data
- Membrane-Enclosed Organelle
- Rate
- Bacteria
- Dna
- Metric System
- Raw Data
- Bar Graph
- Domain
- Mode
- Reductionism
- Biology
- Ecosystem
- Molecule
- Sample
- Biotic
- Emergent Properties
- Natural Selection
- Scatter Plot
- Biosphere
- Error Bar
- Negative Control
- Significant
- Categorical Data
- Eukaryotic Cell
- Normal Distribution
- Slope
- Cell
- Evolution
- Nucleotide
- Standard Deviation
- Chromosome
- Experiment
- Null Hypothesis
- Standard Error Of The Mean
- Climate Change
- Experimental Group
- Observation
- Student T-Test
- Community
- Extinction
- Observational Study
- T-Value
- Confidence
- Flow Of Energy
- Organ
- Tentative
- Confidence Interval
- Fungi
- Organelle
- Theory
- Confounding Variable
- Gene
- Organism
- Tissue
- Continuous Data
- Gene Expression
- Origin Of Species
- Treatment Level
- Control Group
- Hypothesis
- P-Value
- Tree Of Life
- Controlled Experiment
- Hypothesis Test
- Percent Change
- Α (Alpha) Level
- Controlled Variable
- Independent Variable
- Plantae
- Χ2 (Chi-Squared)
- Correlation Coefficient (R)
- Inductive Reasoning
- Population
- Critical Value
- Inference
- Positive Control
- Cycles Of Matter
- Inheritance
- Prediction
- Darwin, Charles
- Kingdom
- Prokaryotic Cell
- Data Table
- Line Of Best Fit
- Protist
Assessments
Unit 2: Biochemistry
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.A: Describe biological concepts and/or processes.
- 2.A: Describe characteristics of a biological concept, process, or model represented visually
AP Biology Course Content Standards
- SYI-1: Living systems are organized in a hierarchy of structural levels that interact.
- SYI-1.A: Explain how the properties of water that result from its polarity and hydrogen bonding affect its biological function.
- SYI-1.B: Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
- SYI-1.C: Explain how a change in the subunits of a polymer may lead to changes in structure or function of the macromolecule.
- ENE-1: The highly complex organization of living systems requires constant input of energy and the exchange of macromolecules.
- ENE-1.A: Describe the composition of macromolecules required by living organisms.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Chemistry Basics & Water
- The subcomponents of biological molecules and their sequence determine the properties of that molecule.
- Living systems depend on properties of water that result from its polarity and hydrogen bonding.
- The hydrogen bonds between water molecules result in cohesion, adhesion, and surface tension.
- Organisms must exchange matter with the environment to grow, reproduce, and maintain organization.
- Atoms and molecules from the environment are necessary to build new molecules—
- Carbon is used to build biological molecules such as carbohydrates, proteins, lipids, and nucleic acids. Carbon is used in storage compounds and cell formation in all organisms.
- Nitrogen is used to build proteins and nucleic acids. Phosphorus is used to build nucleic acids and certain lipids.
Organic Chemistry
- Hydrolysis and dehydration synthesis are used to cleave and form covalent bonds between monomers.
- Structure and function of polymers are derived from the way their monomers are assembled—
- a. In nucleic acids, biological information is encoded in sequences of nucleotide monomers. Each nucleotide has structural components: a five-carbon sugar (deoxyribose or ribose), a phosphate, and a nitrogen base (adenine, thymine, guanine, cytosine, or uracil). DNA and RNA differ in structure and function.
- b. In proteins, the specific order of amino acids in a polypeptide (primary structure) determines the overall shape of the protein. Amino acids have directionality, with an amino (NH2) terminus and a carboxyl (COOH) terminus. The R group of an amino acid can be categorized by chemical properties (hydrophobic, hydrophilic, or ionic), and the interactions of these R groups determine structure and function of that region of the protein.
- c. Complex carbohydrates comprise sugar monomers whose structures determine the properties and functions of the molecules.
- d. Lipids are nonpolar macromolecules—
- Differences in saturation determine the structure and function of lipids.
- Phospholipids contain polar regions that interact with other polar molecules, such as water, and with nonpolar regions that are often hydrophobic.
- Directionality of the subcomponents influences structure and function of the polymer—
- a. Nucleic acids have a linear sequence of nucleotides that have ends, defined by the 3’ hydroxyl and 5’ phosphates of the sugar in the nucleotide. During DNA and RNA synthesis, nucleotides are added to the 3’ end of the growing strand, resulting in the formation of a covalent bond between nucleotides.
- b. DNA is structured as an antiparallel double helix, with each strand running in opposite 5’ to 3’ orientation. Adenine nucleotides pair with thymine nucleotides via two hydrogen bonds. Cytosine nucleotides pair with guanine nucleotides by three hydrogen bonds.
- c. Proteins comprise linear chains of amino acids, connected by the formation of covalent bonds at the carboxyl terminus of the growing peptide chain.
- Proteins have primary structure determined by the sequence order of their constituent amino acids, secondary structure that arises through local folding of the amino acid chain into elements such as alpha-helices and beta-sheets, tertiary structure that is the overall three-dimensional shape of the protein and often minimizes free energy, and quaternary structure that arises from interactions between multiple polypeptide units. The four elements of protein structure determine the function of a protein.
- e. Carbohydrates comprise linear chains of sugar monomers connected by covalent bonds. Carbohydrate polymers may be linear or branched.
Understanding/Key Learning
- The way atoms bond within a molecule plays a critical role in the structural and functional aspects of those molecules
- Water’s structure contributes to its unique ability to support life on Earth, especially with regards to water’s ability to act as a solvent, its thermal properties, and its cohesive properties .
- Large organic molecules have subunits that can be continuously assembled and broken down, which is a key contributor to cellular metabolism
- It is not just which atoms are present in a molecule, but how those atoms are arranged that dictate the molecule’s properties
Do
- Use atomic molecules to predict molecular structures and functions.
- Identify the usefulness and limitations of atomic and molecular models.
- Compare and contrast covalent and ionic bonds.
- Relate polar covalent bonds to the formation of hydrogen bonds.
- Analyze data to demonstrate water’s properties.
- Build digital and physical molecular models of each of the types of monomers.
- Recognize digital and physical molecular models and correctly identify the class of molecule to which those models belong.
- Model the chemical reactions involved in breaking large polymers into individual units, and in building individual units into large polymers.
- Distinguish between the four classes of macromolecules with respect to function, general structure, composition of elements, and locations throughout cells.
- Classify biological molecules as being proteins, carbohydrates, lipids, or proteins.
Unit Essential Questions
Lesson Essential Questions
- How do properties of subatomic particles lead to properties of atoms?
- How do valence electrons dictate the chemical behavior of atoms?
- How does water’s structure lead to its unique properties? How do these properties support life on Earth?
- What are the structures of the four types of large biological molecules? How do these structures relate to their functions?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, MolView others as needed
- Other relevant materials as needed
Vocabulary
- 3’ End
- Covalent Bond
- Hydrogen Bond
- 5’ End
- Cytosine
- Hydrogen Ion
- Acid
- Dehydration Reaction
- Hydrolysis
- Adenine
- Denature
- Hydrophilic
- Adhesion
- Density (Of Ice)
- Hydrophobic
- Amino
- Disaccharide
- Hydroxide Ion
- Amino Acid
- Dna**
- Hydroxyl
- Anabolic
- Double Helix
- Ion
- Anion
- Electron
- Ionic Bond
- Antiparallel
- Electron Cloud
- Isomer
- Atom
- Electron Shell
- Isotope
- Atomic Number
- Electronegativity
- Joule
- Base
- Element
- Kinetic Energy
- Base Pairing
- Enantiomers
- Law Of Conservation Of Energy
- Bioenergetics
- Endergonic / Endothermic
- Law Of Conservation Of Matter
- Buffer
- Energy
- Laws Of Thermodynamics
- Calorie
- Entropy
- Lipid
- Capillary Action
- Enzyme
- Mass Number
- Carbohydrate
- Evaporative Cooling
- Matter
- Carbon
- Exergonic / Exothermic
- Metabolism
- Carboxyl
- Fat
- Methyl
- Catabolic
- Fatty Acid
- Molecule**
- Cation
- Functional Group
- Monomer
- Cellulose
- Glucose
- Monosaccharide
- Chemical Bond
- Glycerol
- Neutral
- Chemical Energy
- Glycogen
- Neutron
- Oil
- Specific Heat
- Organic Molecule
- Spontaneous
- Peptide Bond
- Starch
- Ph
- Steroid
- Phosphate
- Sulfhydryl
- Phosphodiester Bond
- Surface Tension
- Phospholipid
- Temperature
- Polar Covalent Bond
- Tertiary Structure
- Polar Molecule
- Thermal Energy
- Polymer
- Thermodynamics
- Polypeptide
- Trace Element
- Polysaccharide
- Triglyceride
- Potential Energy
- Unsaturated
- Primary Structure
- Valence Number
- Product
- Valence Shell
- Protein
- Water
- Proton
- Purine
- Pyrimidine
- Quaternary Structure
- R Group
- Radioactive Isotope
- Reactant
- Ribosome
- Rna
- Salt
- Saturated
- Secondary Structure
- Solute
- Solution
- Solvent
- Chemical Equilibrium
- Glycosidic Linkage
- Nitrogenous Base
- Chemical Reaction
- Guanine
- Nonpolar Covalent Bond
- Cis-Trans Isomers
- Heat
- Nonpolar Molecule
- Cohesion
- Heat Of Vaporization
- Nucleic Acid
- Compound
- Hydrocarbon
- Nucleotide**
Assessments
Unit 3: Cells & Cell Structure
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.A: Describe biological concepts and/or processes.
- 6.A: Make a scientific claim.
- 2.D.a: Represent relationships within biological models, including mathematical models.
- 5.A.d: Perform mathematical calculations, including ratios.
- 2.A: Describe characteristics of a biological concept, process, or model represented visually.
- 3.D: Make observations or collect data from representations of laboratory steups or results.
- 6.E.a: Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on a biological concept or processes.
- 6.E.b: Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on a visual representation of a biological concept, process, or model.
AP Biology Course Content Standards
- SYI-1: Living systems are organized in a hierarchy of structural levels that interact.
- SYI-1.D: Describe the structure and/ or function of subcellular components and organelles.
- SYI-1.E: Explain how subcellular components and organelles contribute to the function of the cell.
- SYI-1.F: Describe the structural features of a cell that allow organisms to capture, store, and use energy.
- SYI-3 Naturally occurring diversity among and between components within biological systems affects interactions with the environment.
- SYI-3.E Describe the scientific evidence that provides support for models of the origin of life on Earth.
- ENE-1: The highly complex organization of living systems requires constant input of energy and the exchange of macromolecules.
- ENE-1.B: Explain the effect of surface area-to-volume ratios on the exchange of materials between cells or organisms and the environment.
- ENE-1.C: Explain how specialized structures and strategies are used for the efficient exchange of molecules to the environment.
- ENE-2: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments.
- ENE-2.A: Describe the roles of each of the components of the cell membrane in maintaining the internal environment of the cell.
- ENE-2.B: Describe the Fluid Mosaic Model of cell membranes.
- ENE-2.C: Explain how the structure of biological membranes influences selective permeability
- ENE-2.D: Describe the role of the cell wall in maintaining cell structure and function.
- ENE-2.E: Describe the mechanisms that organisms use to maintain solute and water balance.
- ENE-2.F: Describe the mechanisms that organisms use to transport large molecules across the plasma membrane.
- ENE-2.G: Explain how the structure of a molecule affects its ability to pass through the plasma membrane.
- ENE-2.H: Explain how concentration gradients affect the movement of molecules across membranes.
- ENE-2.I: Explain how osmoregulatory mechanisms contribute to the health and survival of organisms.
- ENE-2.J: Describe the processes that allow ions and other molecules to move across membranes.
- ENE-2.K: Describe the membrane-bound structures of the eukaryotic cell.
- ENE-2.L: Explain how internal membranes and membrane-bound organelles contribute to compartmentalization of eukaryotic cell functions.
- EVO-1: Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence.
- EVO-1.A: Describe similarities and/or differences in compartmentalization between prokaryotic and eukaryotic cells.
- EVO-1.B: Describe the relationship between the functions of endosymbiotic organelles and their free-living ancestral counterparts.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Origin of the First Cells on Earth and Cell Types
- Several hypotheses about the origin of life on Earth are supported with scientific evidence—
- a. Geological evidence provides support for models of the origin of life on Earth.
- i. Earth formed approximately 4.6 billion years ago (bya). The environment was too hostile for life until 3.9 bya, and the earliest fossil evidence for life dates to 3.5 bya. Taken together, this evidence provides a plausible range of dates when the origin of life could have occurred.
- b. There are several models about the origin of life on Earth—
- i. Primitive Earth provided inorganic precursors from which organic molecules could have been synthesized because of the presence of available free energy and the absence of a significant quantity of atmospheric oxygen (O2).
- ii. Organic molecules could have been transported to Earth by a meteorite or other celestial event.
- c. Chemical experiments have shown that it is possible to form complex organic molecules from inorganic molecules in the absence of life—
- i. Organic molecules/monomers served as building blocks for the formation of more complex molecules, including amino acids and nucleotides.
- ii. The joining of these monomers produced polymers with the ability to replicate, store, and transfer information.
- a. Geological evidence provides support for models of the origin of life on Earth.
- The RNA World Hypothesis proposes that RNA could have been the earliest genetic material.
- Internal membranes facilitate cellular processes by minimizing competing interactions and by increasing surface areas where reactions can occur.
- Membrane-bound organelles evolved from once free-living prokaryotic cells via endosymbiosis.
- Prokaryotes generally lack internal membrane-bound organelles but have internal regions with specialized structures and functions.
- Eukaryotic cells maintain internal membranes that partition the cell into specialized regions.
- Membranes and membrane-bound organelles in eukaryotic cells compartmentalize intracellular metabolic processes and specific enzymatic reactions.
Organelles Structure and Function
- Organelles and subcellular structures, and the interactions among them, support cellular function—
- a. Endoplasmic reticulum provides mechanical support, carries out protein synthesis on membrane-bound ribosomes, and plays a role in intracellular transport.
- b. Mitochondrial double membrane provides compartments for different metabolic reactions.
- c. Lysosomes contain hydrolytic enzymes, which are important in intracellular digestion, the recycling of a cell’s organic materials, and programmed cell death (apoptosis).
- d. Vacuoles have many roles, including storage and release of macromolecules and cellular waste products. In plants, it aids in retention of water for turgor pressure.
- Lysosomes are membrane-enclosed sacs that contain hydrolytic enzymes.
- A vacuole is a membrane-bound sac that plays many and differing roles. In plants, a specialized large vacuole serves multiple functions.
Organelles of the Endomembrane System
- Ribosomes comprise ribosomal RNA (rRNA) and protein. Ribosomes synthesize protein according to mRNA sequence.
- Ribosomes are found in all forms of life, reflecting the common ancestry of all known life.
- Endoplasmic reticulum (ER) occurs in two forms—smooth and rough. Rough ER is associated with membrane-bound ribosomes—
- a. Rough ER compartmentalizes the cell.
- b. Smooth ER functions include detoxification and lipid synthesis.
- The Golgi complex is a membrane-bound structure that consists of a series of flattened membrane sacs—
- a. Functions of the Golgi include the correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking.
Organelles Involved in Energy Conversion
- Membrane-bound organelles evolved from previously free-living prokaryotic cells via endosymbiosis.
- Mitochondria have a double membrane. The outer membrane is smooth, but the inner membrane is highly convoluted, forming folds.
- Chloroplasts are specialized organelles that are found in photosynthetic algae and plants. Chloroplasts have a double outer membrane.
Cell Membranes and Cell Walls
- Surface area-to-volume ratios affect the ability of a biological system to obtain necessary resources, eliminate waste products, acquire or dissipate thermal energy, and otherwise exchange chemicals and energy with the environment.
- The surface area of the plasma membrane must be large enough to adequately exchange materials—
- a. These limitations can restrict cell size and shape. Smaller cells typically have a higher surface area-to-volume ratio and more efficient exchange of materials with the environment.
- b. As cells increase in volume, the relative surface area decreases and the demand for internal resources increases.
- c. More complex cellular structures (e.g., membrane folds) are necessary to adequately exchange materials within the environment.
- d. As organisms increase in size, their surface area-to-volume ratio decreases, affecting properties like rate of heat exchange with the environment.
- Organisms have evolved highly efficient strategies to obtain nutrients and eliminate wastes. Cells and organisms use specialized exchange surfaces to obtain and release molecules from or into the surrounding environment.
- Phospholipids have both hydrophilic and hydrophobic regions. The hydrophilic phosphate regions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid regions face each other within the interior of the membrane.
- Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups.
- Cell membranes consist of a structural framework of phospholipid molecules that is embedded with proteins, steroids (such as cholesterol in eukaryotes), glycoproteins, and glycolipids that can flow around the surface of the cell within the membrane.
- Cell walls provide a structural boundary, as well as a permeability barrier for some substances to the internal environments.
- Cell walls of plants, prokaryotes, and fungi are composed of complex carbohydrates.
Transport of Materials Across the Membrane
- The structure of cell membranes results in selective permeability.
- Cell membranes separate the internal environment of the cell from the external environment.
- Selective permeability is a direct consequence of membrane structure, as described by the fluid mosaic model.
- A variety of processes allow for the movement of ions and other molecules across membranes, including passive and active transport, endocytosis and exocytosis.
- Growth and homeostasis are maintained by the constant movement of molecules across membranes.
Passive Transport
- Passive transport is the net movement of molecules from high concentration to low concentration without the direct input of metabolic energy
- Passive transport plays a primary role in the import of materials and the export of wastes.
- Small nonpolar molecules, including N2, O2, and CO2, freely pass across the membrane. Hydrophilic substances, such as large polar molecules and ions, move across the membrane through embedded channels and transport proteins.
- Polar uncharged molecules, including H2O, pass through the membrane in small amounts.
- External environments can be hypotonic, hypertonic or isotonic to internal environments of cells—
- a. Water moves by osmosis from areas of high water potential/low osmolarity/ low solute concentration to areas of low water potential/high osmolarity/high solute concentration.
- Osmoregulation maintains water balance and allows organisms to control their internal solute composition/water potential
Active Transport
- Active transport requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration.
- The selective permeability of membranes allows for the formation of concentration gradients of solutes across the membrane.
- Membrane proteins are necessary for active transport.
- Metabolic energy (such as from ATP) is required for active transport of molecules and/ or ions across the membrane and to establish and maintain concentration gradients.
- Membrane proteins are required for facilitated diffusion of charged and large polar molecules through a membrane—
- a. Large quantities of water pass through aquaporins.
- b. Charged ions, including Na+ and K+, require channel proteins to move through the membrane.
- c. Membranes may become polarized by movement of ions across the membrane.
- The Na+/K+ ATPase contributes to the maintenance of the membrane potential.
- The processes of endocytosis and exocytosis require energy to move large molecules into and out of cells—
- a. In exocytosis, internal vesicles fuse with the plasma membrane and secrete large macromolecules out of the cell.
- b. In endocytosis, the cell takes in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane.
Understanding/Key Learning
- Microscopes allowed scientists to develop the cell theory and are still used frequently in scientific discovery.
- Cell structures evolved based on Earth’s conditions and local environments.
- Modern cells are either prokaryotic or eukaryotic, and their structures relate to their evolutionary histories and current functions.
- Components of eukaryotic cells have arisen from various mechanisms, but now work together for the good of the cell (and in multicellular organisms, for the good of the organism) as a whole.
- Membranes are around all cells and surrounding specialized eukaryotic organelles. These membranes have unique structural components that give each membrane a specific function, which includes allowing select materials to enter or exit the cell.
- The movement of materials into and out of the cell is critical for the cell’s ability to maintain homeostasis.
- Particles move at random with their net movement favoring equilibrium, but cellular energy can be spent to establish or maintain a concentration gradient.
- Water, like solutes, follows a concentration gradient. The movement of water into or out of cells (osmosis) can be predicted by calculating water potential.
Do
- Analyze micrographs to determine magnification and actual specimen sizes.
- Compare and contrast micrographs from SEM, TEM, and light microscopes.
- Use a light microscope to find cellular components in pre-made slides from plant and animal tissues.
- Characterize a cell based on its structure.
- Compare and contrast the structural features of prokaryotic (bacterial) and eukaryotic (plant and animal) cells.
- Relate the cell types to their evolutionary histories.
- Explain how cellular life evolved, using evidence from Miller and Urey’s experiments to support your claim.
- Relate the sizes of prokaryotic and eukaryotic cells to their relative complexity and compartmentalization.
- Calculate surface-area-to-volume ratios and use these values to determine a cell’s relative efficiency.
- Identify membrane-bound cellular structures in models and micrographs.
- Know the function of each cellular structure.
- Relate the functions of cellular structures to other structures.
- Describe the structure of cellular membranes.
- Relate the structural components of the cell membranes to their function and permeability.
- Determine whether or not a substance is able to cross the cell membrane.
- Calculate water potential, solute potential, and pressure potential.
- Predict the direction of water movement via osmosis, based on water potential values.
Unit Essential Questions
- What are the key similarities and differences between cell types? How do these reflect both shared ancestry and unique evolutionary steps?
- What are the functional components of cells, and how do these structures contribute to the organization of life?
- How does the movement of materials into and out of the cell enable a cell (and, in multicellular organisms, the organism as a whole) to maintain homeostasis?
Lesson Essential Questions
- What evidence supports the theories of how the first cells on Earth formed?
- How do microscopes allow scientists to study cells?
- How do prokaryotic and eukaryotic cells compare in terms of complexity and size?
- How does surface area to volume ratio constrain each of these cell types?
- How did eukaryotic structures arise? What are the current structures and functions of eukaryotic organelles? (hint: endomembrane system and endosymbionts)
- What are the components of cell membranes?
- How do these components each function in allowing membranes to remain fluid and selectively allow materials into and out of the cell?
- In what ways can particles move into or out of cells?
- How do solute and pressure potentials cause the movement of water into or out of cells?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, MolView others as needed
- Other relevant materials as needed
Vocabulary
- Abiotic Synthesis
- Electron Microscope
- Actin (See Microfilament)
- Endocytosis
- Active Transport
- Endomembrane System
- Amphipathic
- Endoplasmic Reticulum
- Animal*
- Endosymbiotic Theory
- Antiport
- Eukaryotic Cell*
- Aquaporin
- Exocytosis
- Atp
- Extracellular Matrix
- Autophage
- Facilitated Diffusion
- Carrier Protein
- Fimbriae
- Cell Wall
- Flaccid
- Central Vacuole
- Flagella
- Centriole
- Fluid Mosaic Model
- Centrosome
- Free Water
- Channel Protein
- Gap Junction
- Chloroplast
- Gated Channel
- Cholesterol*
- Glycolipid
- Chromatin
- Glycoprotein
- Chromosome*
- Golgi Apparatus
- Cilia
- Golgi: Cis, Trans Faces
- Cisternae
- Granum
- Concentration Gradient
- Histone
- Contractile Vacuole
- Hooke, Robert
- Contrast
- Hydrophilic*
- Cotransport
- Hydrophobic*
- Cristae
- Hypertonic
- Cytoplasm
- Hypotonic
- Cytoskeleton
- Integral Protein
- Cytosol
- Integrin
- Desmosome
- Intermediate Filament
- Diffusion
- Ion Channel
- Dynamic Equilibrium
- Ionization Constant
- Electrochemical Gradient
- Isotonic
- Light Microscope
- Plasmolysis
- Lumen
- Plastid
- Lysosome
- Prokaryotic Cell*
- Magnification
- Protocell
- Membrane-Enclosed (Bound) Organelle*
- Proton Pump
- Membrane Potential
- Receptor-Mediated Endocytosis
- Membrane Sidedness
- Resolution
- Messenger Rna
- Ribosomal Rna
- Microfilament
- Ribosomal Rna
- Microtubule
- Ribosome
- Miller-Urey Experiment
- Ribosome - Free V. Bound
- Mitochondrial Matrix
- Ribozyme
- Mitochondrion
- Rna World Hypothesis
- Motor Protein
- Rough Er
- Nuclear Envelope
- Scale Bars
- Nuclear Pore Complexes
- Sodium-Potassium Pump
- Nucleoid Region
- Stroma
- Nucleolus
- Symport
- Nucleus
- Surface Area To Volume
- Objective Lens
- Thylakoid
- Oparin & Haldane
- Tight Junction
- Organelle*
- Tonicity
- Osmoregulation
- Transmembrane Protein
- Osmosis
- Transmission Electron Mic.
- Passive Transport
- Transport Protein
- Peripheral Protein
- Transport Vesicle
- Peroxisome
- Turgidity / Turgor Pressure
- Phagocytosis
- Vacuole
- Phospholipid*
- Van Leeuwenhoek, Antoni
- Pinocytosis
- Vesicle
- Plant*
- Water Potential
- Plasma (Cell) Membrane
- Ψ (Psi)
- Plasmodesmata
Assessments
Unit 4: Bioenergetics
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.B: Explain biological concepts and/ or processes.
- 3.C.b: Identify experimental procedures that are aligned to the question, including identifying appropriate controls.
- 3.C.c: Identify experimental procedures that are aligned to the question, including justifying appropriate controls.
- 4.A: Construct a graph, plot, or chart.
- 6.C: Provide reasoning to justify a claim by connecting evidence to biological theories.
- 6.B: Support a claim with evidence from biological principles, concepts, processes, and/or data.
- 6.E.c: Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on data.
AP Biology Course Content Standards
- ENE-1: The highly complex organization of living systems requires constant input of energy and the exchange of macromolecules.
- ENE-1.D: Describe the properties of enzymes.
- ENE-1.E: Explain how enzymes affect the rate of biological reactions.
- ENE-1.F: Explain how changes to the structure of an enzyme may affect its function.
- ENE-1.G: Explain how the cellular environment affects enzyme activity
- ENE-1.H: Describe the role of energy in living organisms.
- ENE-1.I: Describe the photosynthetic processes that allow organisms to capture and store energy
- ENE-1.J: Explain how cells capture energy from light and transfer it to biological molecules for storage and use.
- ENE-1.K: Describe the processes that allow organisms to use energy stored in biological macromolecules.
- ENE-1.L: Explain how cells obtain energy from biological macromolecules in order to power cellular functions.
- SYI-3: Naturally occurring diversity among and between components within biological systems affects interactions with the environment.
- SYI-3.A: Explain the connection between variation in the number and types of molecules within cells to the ability of the organism to survive and/or reproduce in different environments.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Laws of Thermodynamics
- All living systems require constant input of energy.
- Life requires a highly ordered system and does not violate the second law of thermodynamics—
- a. Energy input must exceed energy loss to maintain order and to power cellular processes.
- b. Cellular processes that release energy may be coupled with cellular processes that require energy.
- c. Loss of order or energy flow results in death.
- Energy-related pathways in biological systems are sequential to allow for a more controlled and efficient transfer of energy. A product of a reaction in a metabolic pathway is generally the reactant for the subsequent step in the pathway.
Enzyme Structure and Function
- The structure of enzymes includes the active site that specifically interacts with substrate molecules.
- For an enzyme-mediated chemical reaction to occur, the shape and charge of the substrate must be compatible with the active site of the enzyme.
- The structure and function of enzymes contribute to the regulation of biological processes—
- a. Enzymes are biological catalysts that facilitate chemical reactions in cells by lowering the activation energy.
- Change to the molecular structure of a component in an enzymatic system may result in a change of the function or efficiency of the system -
- a. Denaturation of an enzyme occurs when the protein structure is disrupted, eliminating the ability to catalyze reactions.
- b. Environmental temperatures and pH outside the optimal range for a given enzyme will cause changes to its structure, altering the efficiency with which it catalyzes reactions.
- In some cases, enzyme denaturation is reversible, allowing the enzyme to regain activity.
- Environmental pH can alter the efficiency of enzyme activity, including through disruption of hydrogen bonds that provide enzyme structure.
- pH = -log[H+]
- The relative concentrations of substrates and products determine how efficiently an enzymatic reaction proceeds.
- Higher environmental temperatures increase the speed of movement of molecules in a solution, increasing the frequency of collisions between enzymes and substrates and therefore increasing the rate of reaction.
- Competitive inhibitor molecules can bind reversibly or irreversibly to the active site of the enzyme. Noncompetitive inhibitors can bind allosteric sites, changing the activity of the enzyme.
Conversions of Matter & Energy
ATP
- The folding of the inner membrane increases the surface area, which allows for more ATP to be synthesized.
- The conversion of ATP to ADP releases energy, which is used to power many metabolic processes.
Photosynthesis
- Within the chloroplast are thylakoids and the stroma.
- The thylakoids are organized in stacks, called grana.
- Membranes contain chlorophyll pigments and electron transport proteins that comprise the photosystems.
- The light-dependent reactions of photosynthesis occur in the grana.
- The stroma is the fluid within the inner chloroplast membrane and outside of the thylakoid.
- The carbon fixation (Calvin-Benson cycle) reactions of photosynthesis occur in the stroma.
- Organisms capture and store energy for use in biological processes—
- a. Photosynthesis captures energy from the sun and produces sugars.
- i. Photosynthesis first evolved in prokaryotic organisms.
- ii. Scientific evidence supports the claim that prokaryotic (cyanobacterial) photosynthesis was responsible for the production of an oxygenated atmosphere.
- Prokaryotic photosynthetic pathways were the foundation of eukaryotic photosynthesis.
- a. Photosynthesis captures energy from the sun and produces sugars.
- The light-dependent reactions of photosynthesis in eukaryotes involve a series of coordinated reaction pathways that capture energy present in light to yield ATP and NADPH, which power the production of organic molecules.
- During photosynthesis, chlorophylls absorb energy from light, boosting electrons to a higher energy level in photosystems I and II.
- Photosystems I and II are embedded in the internal membranes of chloroplasts and are connected by the transfer of higher energy electrons through an electron transport chain (ETC).
- When electrons are transferred between molecules in a sequence of reactions as they pass through the ETC, an electrochemical gradient of protons (hydrogen ions) is established across the internal membrane.
- The formation of the proton gradient is linked to the synthesis of ATP from ADP and inorganic phosphate via ATP synthase.
- The energy captured in the light reactions and transferred to ATP and NADPH powers the production of carbohydrates from carbon dioxide in the Calvin cycle, which occurs in the stroma of the chloroplast.
Cellular Respiration
- The Krebs cycle (citric acid cycle) reactions occur in the matrix of the mitochondria.
- Electron transport and ATP synthesis occur on the inner mitochondrial membrane.
- Fermentation and cellular respiration use energy from biological macromolecules to produce ATP. Respiration and fermentation are characteristic of all forms of life.
- Cellular respiration in eukaryotes involves a series of coordinated enzyme-catalyzed reactions that capture energy from biological macromolecules.
- The electron transport chain transfers energy from electrons in a series of coupled reactions that establish an electrochemical gradient across membranes—
- a. Electron transport chain reactions occur in chloroplasts, mitochondria, and prokaryotic plasma membranes.
- b. In cellular respiration, electrons delivered by NADH and FADH2 are passed to a series of electron acceptors as they move toward the terminal electron acceptor, oxygen. In photosynthesis, the terminal electron acceptor is NADP+. Aerobic prokaryotes use oxygen as a terminal electron acceptor, while anaerobic prokaryotes use other molecules.
- C. The transfer of electrons is accompanied by the formation of a proton gradient across the inner mitochondrial membrane or the internal membrane of chloroplasts, with the membrane(s) separating a region of high proton concentration from a region of low proton concentration. In prokaryotes, the passage of electrons is accompanied by the movement of protons across the plasma membrane.
- d. The flow of protons back through membrane-bound ATP synthase by chemiosmosis drives the formation of ATP from ADP and inorganic phosphate. This is known as oxidative phosphorylation in cellular respiration, and photophosphorylation in photosynthesis.
- e. In cellular respiration, decoupling oxidative phosphorylation from electron transport generates heat. This heat can be used by endothermic organisms to regulate body temperature.
- Glycolysis is a biochemical pathway that releases energy in glucose to form ATP from ADP and inorganic phosphate, NADH from NAD+, and pyruvate.
- Pyruvate is transported from the cytosol to the mitochondrion, where further oxidation occurs.
- In the Krebs cycle, carbon dioxide is released from organic intermediates, ATP is synthesized from ADP and inorganic phosphate, and electrons are transferred to the coenzymes NADH and FADH2.
- Electrons extracted in glycolysis and Krebs cycle reactions are transferred by NADH and FADH2 to the electron transport chain in the inner mitochondrial membrane.
- When electrons are transferred between molecules in a sequence of reactions as they pass through the ETC, an electrochemical gradient of protons (hydrogen ions) across the inner mitochondrial membrane is established.
- Fermentation allows glycolysis to proceed in the absence of oxygen and produces organic molecules, including alcohol and lactic acid, as waste products.
Understanding/Key Learning
- Energy can be converted between different forms, which always increases the entropy of the universe.
- Maintaining biological order requires a constant input of energy, which may come from different sources depending on the type of organism.
- Chemical reactions can be endergonic or exergonic, but almost always require an input of at least some activation energy to get started.
- Enzymes work as biological catalysts to allow the biochemical reactions of our cells to occur at temperatures that are compatible with life.
- ATP are cellular “batteries” then enable cells to function.
- Photosynthesis and cellular respiration both produce ATP but harness energy from different initial sources. Both evolved as ways for organisms to obtain necessary energy.
- Structural components of the mitochondria and chloroplast enable these organelles to function as sites of cellular respiration and photosynthesis, respectively.
Do
- Calculate and graph rates of reactions for enzyme-catalyzed and non-enzyme-catalyzed biochemical reactions.
- Use data to determine optimal conditions for enzymes.
- Design and carry out an experiment to test factors that affect an enzyme’s ability to function over a range of environmental conditions.
- Produce a model to show the conversion between adenosine tri-phosphate (ATP) and adenosine di-phosphate (ADP), including energy absorption and release.
- Identify the parts of mitochondria and chloroplasts and relate their structures to their specific functions.
- Interpret diagrams that show the individual steps of photosynthesis and cellular respiration, including all inputs, outputs, energy conversions, and cellular locations.
- State the overall chemical reactions for photosynthesis and cellular respiration.
- Produce a model to show the process of cellular respiration, with attention to the movement of energy and matter throughout glycolysis, the link reaction, the Krebs cycle, and oxidative phosphorylation.
- Produce a model to show the process of photosynthesis, with attention to the conversion of electromagnetic energy to chemical energy during the light dependent reactions and with attention to the movement of matter and energy during the Calvin cycle.
- Interpret the results of experiments that show how different variables can affect the rate of cellular respiration and/or photosynthesis.
- Predict the consequences of limiting factors on the rate of photosynthesis.
Unit Essential Questions
Lesson Essential Questions
- How do cells use exergonic reactions for cellular work?
- How do enzymes enable chemical reactions to happen in cells?
- What conditions affect an enzyme’s ability to catalyze reactions?
- What are redox reactions? How are they used to extract energy in molecules for cells to use?
- What are the matter and energy conversions that happen during each stage of photosynthesis?
- What is the purpose and process of glucose oxidation?
- How are the products of glucose oxidation used in oxidative phosphorylation to make ATP?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vocabulary
- Absorption
- Citric Acid Cycle
- Absorption Spectrum
- Coenzyme
- Acetyl Coa
- Cofactor
- Action Spectrum
- Competitive Inhibitor
- Activation Energy
- Cristae*
- Activator
- Denature*
- Active Site
- Electrochemical Gradient
- Adp
- Electromagnetic Spectrum
- Aerobic Respiration
- Electron Carrier
- Alcohol Fermentation
- Electron Transport Chain
- Allosteric Regulation
- Electronegative*
- Allosteric Site
- End Product Inhibition
- Anabolic*
- Endergonic*
- Anaerobic
- Energy Coupling
- Atp
- Energy Investment
- Atp Synthase
- Energy Payoff
- Autotroph
- Energy*
- C3 / C4 / Cam Plants
- Entropy*
- Calvin Cycle
- Enzyme-Substrate Complex
- Carbon Fixation
- Enzyme*
- Carotenoid
- Exergonic*
- Catabolic*
- Fad /Fadh2
- Catalyst
- Feedback Inhibition
- Cellular Respiration
- Fermentation
- Chemiosmosis
- Final Electron Acceptor
- Chlorophyll
- Free Energy (Gibbs)
- Chloroplast*
- G3p / Pgal
- Glucose*
- Photolysis
- Glycolysis
- Photon
- Heterotroph
- Photophosphorylation
- Induced Fit
- Photosynthesis
- Inhibitor
- Photosystem
- Intermembrane Space
- Pigment
- Krebs Cycle
- Protein
- Lactic Acid Fermentation
- Pyruvate
- Light Dependent Reaction
- Rate Of Reaction
- Light Independent Reactions
- Redox Reaction
- Light-Harvesting Complex
- Reduction
- Lock-And-Key Model
- Reflection
- Mesophyll
- Rubisco
- Metabolic Pathway
- Rubp
- Mitochondria*
- Saturated (Enzymes)
- Mitochondrial Matrix*
- Specificity
- Nad+/ Nadh
- Spontaneous*
- Nadp+/Nadph
- Stomata
- Negative Feedback
- Stroma*
- Noncompetitive Inhibitor
- Substrate
- Optimal Condition
- Substrate-Level Phosphorylation
- Organic*
- Thermodynamics*
- Oxidation
- Thylakoid*
- Oxidative Phosphorylation
- Transition State
- pH*
- Visible Light
- Phosphate*
- Wavelength
- Phosphorylation
Assessments
Unit 5: Molecular Genetics
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vobulary
- Assessments
Standards
AP Biology Science Practices
- 1.C Explain biological concepts, processes, and/or models in applied contexts.
- 2.B.b Explain relationships between different characteristics of biological concepts, processes, or models represented visually in applied contexts.
- 2.C Explain how biological concepts or processes represented visually relate to larger biological principles, concepts, processes, or theories.
- 2.D.b Represent relationships within biological models, including diagrams.
- 3.D Make observations or collect data from representations of laboratory setups or results.
- 6.A Make a scientific claim.
- 6.B Support a claim with evidence from biological principles, concepts, processes, and/or data.
- 6.D Explain the relationship between experimental results and larger biological concepts, processes, or theories
- 6.E.a Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on biological concepts.
AP Biology Course Content Standards
- IST-1: Heritable information provides for continuity of life.
- IST-1.A: Describe the structural similarities and differences between DNA and RNA.
- IST-1.K Describe the structures involved in passing hereditary information from one generation to the next.
- IST-1.L Describe the characteristics of DNA that allow it to be used as the hereditary material.
- IST-1.M Describe the mechanisms by which genetic information is copied for transmission between generations.
- IST-1.N Describe the mechanisms by which genetic information flows from DNA to RNA to protein.
- IST-1.O Explain how the phenotype of an organism is determined by its genotype.
- IST-1.P Explain the use of genetic engineering techniques in analyzing or manipulating DNA.
- IST-2 Differences in the expression of genes account for some of the phenotypic differences between organisms.
- IST-2.A Describe the types of interactions that regulate gene expression.
- IST-2.B Explain how the location of regulatory sequences relates to their function.
- IST-2.C Explain how the binding of transcription factors to promoter regions affects gene expression and/or the phenotype of the organism.
- IST-2.D Explain the connection between the regulation of gene expression and phenotypic differences in cells and organisms.
- IST-2.E Describe the various types of mutation.
- IST-4 The processing of genetic information is imperfect and is a source of genetic variation.
- IST-4.A Explain how changes in genotype may result in changes in phenotype.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Nucleic Acid Structure and Function
- DNA and RNA are carriers of genetic information.
- DNA, and in some cases RNA, is the primary source of heritable information.
- Genetic information is transmitted from one generation to the next through DNA or RNA—
- a. Genetic information is stored in and passed to subsequent generations through DNA molecules and, in some cases, RNA molecules.
- b. Prokaryotic organisms typically have circular chromosomes, while eukaryotic organisms typically have multiple linear chromosomes.
- Prokaryotes and eukaryotes can contain plasmids, which are small extra-chromosomal, double-stranded, circular DNA molecules.
- DNA, and sometimes RNA, exhibits specific nucleotide base pairing that is conserved through evolution: adenine pairs with thymine or uracil (A-T or A-U) and cytosine pairs with guanine (C-G)—
- a. Purines (G and A) have a double ring structure.
- b. Pyrimidines (C, T, and U) have a single ring structure.
- DNA and RNA molecules have structural similarities and differences related to their function—
- a. Both DNA and RNA have three components—sugar, a phosphate group, and a nitrogenous base—that form nucleotide units that are connected by covalent bonds to form a linear molecule with 5’ and 3’ ends, with the nitrogenous bases perpendicular to the sugar-phosphate backbone.
- b. The basic structural differences between DNA and RNA include the following:
- i. DNA contains deoxyribose and RNA contains ribose.
- ii. RNA contains uracil and DNA contains thymine.
- iii. DNA is usually double stranded; RNA is usually single stranded.
- iv. The two DNA strands in double-stranded DNA are antiparallel in directionality.
DNA Replication
- DNA replication ensures continuity of hereditary information—
- a. DNA is synthesized in the 5’ to 3’ direction.
- b. Replication is a semiconservative process—that is, one strand of DNA serves as the template for a new strand of complementary DNA.
- c. Helicase unwinds the DNA strands.
- d. Topoisomerase relaxes supercoiling in front of the replication fork.
- e. DNA polymerase requires RNA primers to initiate DNA synthesis.
- f. DNA polymerase synthesizes new strands of DNA continuously on the leading strand and discontinuously on the lagging strand.
- g. Ligase joins the fragments on the lagging strand.
Gene Expression and Regulation
- Ribosomes are found in all forms of life.
- The sequence of the RNA bases, together with the structure of the RNA molecule, determines RNA function—
- a. mRNA molecules carry information from DNA to the ribosome.
- b. Distinct tRNA molecules bind specific amino acids and have anti-codon sequences that base pair with the mRNA. tRNA is recruited to the ribosome during translation to generate the primary peptide sequence based on the mRNA sequence.
- c. rRNA molecules are functional building blocks of ribosomes.
- Genetic information flows from a sequence of nucleotides in DNA to a sequence of bases in an mRNA molecule to a sequence of amino acids in a protein.
Transcription
- RNA polymerases use a single template strand of DNA to direct the inclusion of bases in the newly formed RNA molecule. This process is known as transcription.
- The DNA strand acting as the template strand is also referred to as the noncoding strand, minus strand, or antisense strand. Selection of which DNA strand serves as the template strand depends on the gene being transcribed.
- The enzyme RNA polymerase synthesizes mRNA molecules in the 5’ to 3’ direction by reading the template DNA strand in the 3’ to 5’ direction.
- In eukaryotic cells the mRNA transcript undergoes a series of enzyme-regulated modifications—
- a. Addition of a poly-A tail.
- b. Addition of a GTP cap.
- c. Excision of introns and splicing and retention of exons.
- d. Excision of introns and splicing and retention of exons can generate different versions of the resulting mRNA molecule; this is known as alternative splicing.
Translation
- Translation of the mRNA to generate a polypeptide occurs on ribosomes that are present in the cytoplasm of both prokaryotic and eukaryotic cells and on the rough endoplasmic reticulum of eukaryotic cells.
- In prokaryotic organisms, translation of the mRNA molecule occurs while it is being transcribed.
- Translation involves energy and many sequential steps, including initiation, elongation, and termination.
- The salient features of translation include—
- a. Translation is initiated when the rRNA in the ribosome interacts with the mRNA at the start codon.
- b. The sequence of nucleotides on the mRNA is read in triplets called codons.
- c. Each codon encodes a specific amino acid, which can be deduced by using a genetic code chart. Many amino acids are encoded by more than one codon.
- d. Nearly all living organisms use the same genetic code, which is evidence for the common ancestry of all living organisms.
- e. tRNA brings the correct amino acid to the correct place specified by the codon on the mRNA.
- f. The amino acid is transferred to the growing polypeptide chain.
- g. The process continues along the mRNA until a stop codon is reached.
- h. The process terminates by release of the newly synthesized polypeptide/protein.
- Genetic information in retroviruses is a special case and has an alternate flow of information: from RNA to DNA, made possible by reverse transcriptase, an enzyme that copies the viral RNA genome into DNA. This DNA integrates into the host genome and becomes transcribed and translated for the assembly of new viral progeny.
Regulation of Gene Expression
- Regulatory sequences are stretches of DNA that interact with regulatory proteins to control transcription.
- Epigenetic changes can affect gene expression through reversible modifications of DNA or histones
- The phenotype of a cell or organism is determined by the combination of genes that are expressed and the levels at which they are expressed—
- a. Observable cell differentiation results from the expression of genes for tissue-specific proteins.
- b. Induction of transcription factors during development results in sequential gene expression.
- Both prokaryotes and eukaryotes have groups of genes that are coordinately regulated—
- a. In prokaryotes, groups of genes called operons are transcribed in a single mRNA molecule. The lac operon is an example of an inducible system.
- b. In eukaryotes, groups of genes may be influenced by the same transcription factors to coordinately regulate expression.
- Promoters are DNA sequences upstream of the transcription start site where RNA polymerase and transcription factors bind to initiate transcription.
- Negative regulatory molecules inhibit gene expression by binding to DNA and blocking transcription.
- Gene regulation results in differential gene expression and influences cell products and function.
- Certain small RNA molecules have roles in regulating gene expression.
Mutations
- Changes in genotype can result in changes in phenotype—
- a. The function and amount of gene products determine the phenotype of organisms.
- i. The normal function of the genes and gene products collectively comprises the normal function of organisms.
- ii. Disruptions in genes and gene products cause new phenotypes.
- a. The function and amount of gene products determine the phenotype of organisms.
- Alterations in a DNA sequence can lead to changes in the type or amount of the protein produced and the consequent phenotype. DNA mutations can be positive, negative, or neutral based on the effect or the lack of effect they have on the resulting nucleic acid or protein and the phenotypes that are conferred by the protein.
- Errors in DNA replication or DNA repair mechanisms, and external factors, including radiation and reactive chemicals, can cause random mutations in the DNA—
- a. Whether a mutation is detrimental, beneficial, or neutral depends on the environmental context.
- b. Mutations are the primary source of genetic variation.
Biotechnology
- Major features of the genetic code are shared by all modern living systems.
- Genetic engineering techniques can be used to analyze and manipulate DNA and RNA—
- a. Electrophoresis separates molecules according to size and charge.
- b. During polymerase chain reaction (PCR), DNA fragments are amplified
- c. Bacterial transformation introduces DNA into bacterial cells.
- d. DNA sequencing determines the order of nucleotides in a DNA molecule.
Understanding/Key Learning
- The “flow” of genetic information is from the information encoded in DNA, to RNA, to proteins. There are few exceptions to this “central dogma” of DNA, including that of viruses, which may use RNA to reverse transcribe DNA.
- DNA is packaged into discrete units, called chromosomes, which are found in and identical amongst (almost) all cells of a multicellular organism.
- An understanding of DNA’s structure and function required the collaborative efforts of many naturalists and scientists throughout the early- and mid- twentieth centuries. Modern scientists are continuing the work of understanding how genetic information is used to produce phenotypes.
- DNA has a special structure that enables it to be copied, and to be used as a blueprint for the production of other molecules in the cell.
- Errors in the copying of DNA (mutations) can result in beneficial, neutral, or harmful effects.
- All genetic variability on Earth arises from mutations.
- Cells have specialized structures that enable them to utilize the genetic information from DNA to build proteins.
- Viruses are acellular particles that contain their own genes made of either DNA and RNA, but require cellular mechanisms for replication and for the production of viral proteins.
- Cells must carefully regulate the timing of gene expression based on environmental conditions and nutrient availability, and for multicellular organisms, the location within an organism.
- Genetic engineering and biotechnology uses our knowledge of the genome, how DNA is copied, and how genes are expressed to manipulate DNA for human use.
Do
- Relate the terms genome, gene, chromosome, phenotype, genotype, and DNA.
- Interpret the results of experiments from Thomas Hunt Morgan; Hershey and Chase; Frederick Griffith, Avery, McCarty, and MacLeod; Erwin Chargaff; Rosalind Franklin; and Watson and Crick. Relate each to its role in the discovery of DNA’s structure.
- Model DNA from the perspective of individual nucleotides up to the molecule as a whole.
- Determine DNA sequences based on complementary strands of DNA.
- Determine mRNA sequences based on complementary strands of DNA.
- Relate the structures and functions of mRNA, rRNA, and tRNA.
- Use models to show the processes of transcription and translation in prokaryotic and eukaryotic cells.
- Determine polypeptide sequences based on DNA or mRNA sequences, using wheel and table-style codon charts.
- Compare and contrast the processes of DNA replication, transcription, and translation, including all relevant enzymes and cofactors needed for each process, the location, and any differences that occur between prokaryotic and eukaryotic cells.
- Interpret operon models to predict when prokaryotic cells would or would not express certain genes.
- Explain how eukaryotic organisms can regulate their gene expression.
- Describe the importance of gene regulation in eukaryotes (especially multicellular ones).
- Construct an argument for and against the use of biotechnology for a range of current and potential uses.
Unit Essential Questions
Lesson Essential Questions
- How are organism’s genomes able to fit into their cells? Distinguish between prokaryotic and eukaryotic genomes.
- How did specific scientists contribute to the understanding of DNA as the genetic material? Its structure?
- How does the “specific pairing… postulated” by Watson and Crick “immediately suggests a possible copying mechanism” for DNA?
- How is genetic information expressed in cells?
- How do prokaryotes use operons to control gene expression?
- What can eukaryotes do to control gene expression? How does this relate to their complexity and multicellularity?
- How can scientists use and manipulate DNA?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vobulary
- 3’ End*
- Enhancer
- 5’ Cap
- Epigenetics
- 5’ End*
- Euchromatin
- Activator
- Exon
- Alternative Rna Splicing
- Feedback Inhibition
- Aminoacyl-Trna-Synthetase
- Frameshift Mutation
- Anticodon
- Franklin, Rosalind
- Antiparallel*
- Gel Electrophoresis
- Bacteriophage
- Gene Cloning
- Base Pairing
- Gene Expression*
- Central Dogma
- Genetic Code
- Chargaff, Erwin
- Genetic Engineering
- Chargaff’s Rule
- Genome*
- Charged Trna
- Griffith, Frederick
- Chromatin*
- Helicase
- Chromosomal Theory Of Inheritance
- Hershey & Chase
- Chromosome**
- Heterochromatin
- Cloning Vector
- Histone
- Coding Strand
- Histone Acetylation
- Codon
- Histone Modification
- Complementary
- Inducer
- Control Elements
- Inducible Operon
- Corepressor
- Initiation^
- Crispr-Cas9
- Insertion / Deletion
- Cyclic Amp
- Intron
- Differential Gene Expression
- Junk Dna
- Dna Cloning
- Lagging Strand
- Dna Ligase
- Leading Strand
- Dna Methylation
- Locus (Or Gene Loci)
- Dna Polymerase
- Maselson & Stahl
- Dna Profiling
- Messenger Rna (Mrna)
- Dna Replication
- Mismatch Repair
- Dna Sequencing
- Missense Mutation
- Double Helix
- Morgan, Thomas H
- Elongation^
- Mutagen
- Mutation
- Ribosomal Subunits
- Noncoding Rna
- Ribosome*
- Nuclease
- Ribozyme*
- Nucleosome
- Rna Interference
- Nucleotide**
- Rna Polymerase
- Okazaki Fragment
- Rna Processing
- One-Gene One-Protein
- Rna Splicing
- Operator
- Semiconservative Model
- Operon
- Signal Peptide
- Origin Of Replication
- Silent Mutation
- Plasmid*
- Single-Strand Binding Proteins
- Point Mutation
- Spliceosome
- Poly-A Tail
- Sticky End
- Polymerase Chain Reaction (Pcr)
- Substitution
- Positive Gene Regulation
- Taq Polymerase
- Post-Translational Modification
- Tata Box
- Primase
- Telomerase
- Primer
- Telomere
- Promoter
- Template Strand
- Protein**
- Termination^
- Purine*
- Terminator
- Pyrimidine*
- Topoisomerase
- Reading Frame
- Transcription
- Recombinant Dna
- Transcription Factor
- Regulatory Gene
- Transcription Initiation Complex
- Release Factor
- Transcription Unit
- Replication Bubble
- Transfer Rna (Trna)
- Replication Fork
- Transformation
- Repressible Operon
- Translation
- Repressor
- Translation Initiation Complex
- Restriction Enzyme
- Triplet Code
- Restriction Fragment
- Watson & Crick
- Restriction Site
- Wobble
- Ribosomal Rna (Rrna)*
- X-Ray Crystallography
Assessments
Unit 6: Multicellularity
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.B: Explain biological concepts and/or processes.
- 1.A: Describe biological concepts and/or processes.
- 4.B.b: Describe data from a table or graph, including describing trends and/or patterns in the data.
- 5.A.e: Perform mathematical calculations, including percentages.
- 6.C: Provide reasoning to justify a claim by connecting evidence to biological theories.
- 6.E.a: Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on biological concepts or processes.
- 6.E.b: Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on a visual representation of a biological concept, process, or model.
AP Biology Course Content Standards
- IST-3: Cells communicate by generating, transmitting, receiving, and responding to chemical signals.
- IST-3.A: Describe the ways that cells can communicate with one another.
- IST-3.B: Explain the ways that cells can communicate with one another over short and long distances.
- IST-3.C: Describe the components of a signal transduction pathway.
- IST-3.D: Describe the role of components of a signal transduction pathway in producing a cellular response.
- IST-3.E: Describe the role of the environment in eliciting a cellular response.
- IST-3.F: Describe the different types of cellular responses elicited by a signal transduction pathway.
- IST-3.G: Explain how a change in the structure of any signaling molecule affects the activity of the signaling pathway.
- ENE-3: Timing and coordination of biological mechanisms involved in growth, reproduction, and homeostasis depend on organisms responding to environmental cues.
- ENE-3.A: Describe positive and/ or negative feedback mechanisms.
- ENE-3.B: Explain how negative feedback helps to maintain homeostasis.
- ENE-3.C: Explain how positive feedback affects homeostasis.
- IST-1: Heritable information provides for continuity of life.
- IST-1.B: Describe the events that occur in the cell cycle.
- IST-1.C: Explain how mitosis results in the transmission of chromosomes from one generation to the next.
- IST-1.D: Describe the role of checkpoints in regulating the cell cycle.
- IST-1.E: Describe the effects of disruptions to the cell cycle on the cell or organism.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Cell Communication
- Cells communicate with one another through direct contact with other cells or from a distance via chemical signaling—
- a. Cells communicate by cell-to-cell contact.
- Cells communicate over short distances by using local regulators that target cells in the vicinity of the signal-emitting cell —
- a. Signals released by one cell type can travel long distances to target cells of another cell type.
- Signal transduction pathways link signal reception with cellular responses.
- Many signal transduction pathways include protein modification and phosphorylation cascades.
- Signaling begins with the recognition of a chemical messenger—a ligand—by a receptor protein in a target cell—
- a. The ligand-binding domain of a receptor recognizes a specific chemical messenger, which can be a peptide, a small chemical, or protein, in a specific one-to-one relationship.
- b. G protein-coupled receptors are an example of a receptor protein in eukaryotes.
- Signaling cascades relay signals from receptors to cell targets, often amplifying the incoming signals, resulting in the appropriate responses by the cell, which could include cell growth, secretion of molecules, or gene expression—
- a. After the ligand binds, the intracellular domain of a receptor protein changes shape initiating transduction of the signal.
- b. Second messengers (such as cyclic AMP) are molecules that relay and amplify the intracellular signal.
- c. Binding of ligand-to-ligand-gated channels can cause the channel to open or close.
- Signal transduction pathways influence how the cell responds to its environment.
- Signal transduction may result in changes in gene expression and cell function, which may alter phenotype or result in programmed cell death (apoptosis)
- Changes in signal transduction pathways can alter cellular response—
- a. Mutations in any domain of the receptor protein or in any component of the signaling pathway may affect the downstream components by altering the subsequent transduction of the signal.
- Chemicals that interfere with any component of the signaling pathway may activate or inhibit the pathway
Mechanisms of Homeostasis
- Organisms use feedback mechanisms to maintain their internal environments and respond to internal and external environmental changes.
- Negative feedback mechanisms maintain homeostasis for a particular condition by regulating physiological processes. If a system is perturbed, negative feedback mechanisms return the system back to its target set point. These processes operate at the molecular and cellular levels.
- Positive feedback mechanisms amplify responses and processes in biological organisms. The variable initiating the response is moved farther away from the initial set point. Amplification occurs when the stimulus is further activated, which, in turn, initiates an additional response that produces system change.
Cell Cycle
- In eukaryotes, cells divide and transmit genetic information via two highly regulated processes.
- The cell cycle is a highly regulated series of events for the growth and reproduction of cells—
- a. The cell cycle consists of sequential stages of interphase (G1, S, G2), mitosis, and cytokinesis.
- b. A cell can enter a stage (G0) where it no longer divides, but it can reenter the cell cycle in response to appropriate cues. Nondividing cells may exit the cell cycle or be held at a particular stage in the cell cycle.
- Mitosis is a process that ensures the transfer of a complete genome from a parent cell to
- two genetically identical daughter cells—
- a. Mitosis plays a role in growth, tissue repair, and asexual reproduction.
- b. Mitosis alternates with interphase in the cell cycle.
- c. Mitosis occurs in a sequential series of steps (prophase, metaphase, anaphase, telophase).
- A number of internal controls or checkpoints regulate progression through the cycle.
- Interactions between cyclins and cyclin-dependent kinases control the cell cycle.
- Disruptions to the cell cycle may result in cancer and/or programmed cell death (apoptosis).
Understanding/Key Learning
- The evolution of multicellularity allowed early organisms to have a size advantage, and have resulted in emergent properties as complexity increased.
- Cells within a multicellular organisms must have novel abilities that are not required for unicellular organisms, including:
- Mechanisms to communicate and coordinate activities
- Cell specialization, where cells with identical genomes can become differentiated to perform specific tasks for the organisms as a whole
- Unique means reproduction, as a consequence of two factors: (1) having multiple chromosomes; and (2) having distinct “body” and “germ” cells
- Body systems in vertebrates provide specialized means of carrying out life processes and maintaining homeostasis, including systems for:
- Exchanging material with the environment (digestive, excretory, respiratory)
- Coordinating other body systems (nervous, endocrine)
- Delivering materials to all cells within the organism (cardiovascular)
- Negative feedback is a mechanism where organisms respond to stimuli by counteracting the stimulus, which is used for maintaining homeostasis.
- Positive feedback is a mechanism where organisms respond to stimuli by amplifying the stimulus, which is used for producing some physiological effect.
- Eukaryotic cells each contain multiple chromosomes, which must be carefully sorted when a cell divides into two, ensuring that each daughter cell receives the appropriate combination of chromosomes. This can be done via the process of mitosis.
- A cell’s “life cycle” includes a period of growth and, potentially, a period of division. These events are carefully controlled and coordinated by internal and external factors. Failure of the cell to respond appropriately to said factors can result in cell death or tumor formation and/or cancer.
Do
- Compare how unicellular and multicellular organisms maintain homeostasis.
- Describe the parts of a negative feedback loop.
- Construct a diagram to show negative feedback mechanisms relating to thermoregulation and either oxygen regulation, osmotic regulation, or glucose regulation.
- Predict the consequences of a failure of homeostasis.
- Identify and describe the parts of a positive feedback loop, using childbirth or breastfeeding as examples.
- Justify the importance of cell communication for multicellular organisms.
- Identify the types of cell communication based on ligands, the system(s) involved, and the distance traveled by the ligand to its target cell.
- Compare and contrast small, nonpolar ligands to large and/or polar ones in terms of their mode of effect on a target cell.
- Interpret diagrams showing cell signaling pathways; using diagrams, be able to identify the receptor, ligand, transduction pathway with relevant second messengers, kinases, or other relay proteins, and the response(s).
- Explain how an extracellular stimulus can cause a cellular response.
- Describe the parts of the cell cycle.
- Model the movement of chromosomes during each part of the cell cycle and nuclear division (specifically, mitosis).
- Identify the stage of mitosis in plant and animal cells in diagrams and micrographs.
- Predict the outcomes that would result from an error at any point of the cell cycle and/or nuclear division.
- Describe how cells regulate the timing of cell division.
- Calculate mitotic indices and explain why indices of different cell types would vary.
- Relate the control mechanisms for the cell cycle to the formation of tumor and cancers.
- Distinguish between benign tumors and malignant tumors/cancers.
- Interpret models or diagrams that show cell differentiation in multicellular organisms.
Unit Essential Questions
Lesson Essential Questions
- How and why do cells in multicellular organisms communicate?
- How do chemical messages outside of cells lead to changes in cellular behavior?
- How is negative feedback used by organisms to maintain homeostasis?
- What systems coordinate human functions? How?
- What process enables new cells to contain full complements of the genome?
- How is the cell cycle regulated?
- How can a single cell divide to become all of the specialized cells of a mature organism?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vocabulary
- Adenylyl Cyclase
- Endothermy
- Amplification
- Evo-Devo
- Anaphase
- Extracellular Matrix (Ecm)*
- Apoptosis
- Fever
- Benign
- G Protein
- Binary Fission
- G Protein-Coupled Receptor (GPCR)
- cAmp*
- G0 Phase
- Cancer
- G1 Phase
- Cell Cycle Control System
- G2 Phase
- Cell Plate
- Gap Junction*
- Centriole*
- Gland
- Centromere
- Growth Factor
- Centrosome
- Homeostasis
- Checkpoint
- Homeotic Gene
- Chromatin*
- Hormone
- Cleavage Furrow
- Induced Pluripotent Stem Cells (Ips)
- Conformer
- Interphase
- Countercurrent Exchange
- Interstitial Fluid
- Cytokinesis
- Intracellular Receptor
- Cytoplasmic Determinant
- Kinase
- Daughter Cell
- Kinetochore
- Density-Dependent Inhibition
- Ligand
- Dephosphorylation
- Ligand-Gated Ion Channel
- Desmosome
- Malignant
- Differentiation
- Maternal Effect Gene
- Embryo
- Metaphase
- Endocrine Signaling
- Metaphase Plate
- Endocrine System
- Metastasis
- Microtubule
- Response
- Mitosis
- Restriction Point
- Mitotic Phase
- S Phase
- Morphogenesis
- Second Messenger
- Multipotent
- Sensor
- Negative Feedback*
- Set Point
- Nervous System
- Signal Transduction Pathway
- Oncogene
- Sister Chromatid
- Organ System*
- Somatic Cell
- Organ*
- Spindle Fiber (Mitotic Spindle)
- P53 Gene
- Stem Cell
- Paracrine Signaling
- Stimulus
- Pattern Formation
- Synaptic Signaling
- Phosphatase
- Telophase
- Phosphorylation
- Therapeutic Cloning
- Phosphorylation Cascade
- Thermoregulation
- Plasmodesma*
- Tight Junction*
- Pluripotent
- Totipotent
- Positive Feedback
- Transcription Factor*
- Prometaphase
- Transduction
- Prophase
- Transduction
- Proto-Oncogene
- Transformation
- Ras Gene
- Tumor
- Reception
- Tumor Suppressor Gene
- Regulator
- Vasoconstriction
- Relay Molecule
- Vasodilation
- Reproductive Cloning
- Zygote
Assessments
Unit 7: Inheritance
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.B Explain biological concepts and/or processes.
- 1.C Explain biological concepts, processes, and/or models in applied contexts.
- 3.A Identify or pose a testable question based on an observation, data, or a model.
- 5.A.b Perform mathematical calculations, including means.
- 5.C Perform chi-square hypothesis testing.
- 6.E.b Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on a visual representation of a biological concept, process, or model.
- 6.E.c Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on data.
AP Biology Course Content Standards
- IST-1 Heritable information provides for continuity of life.
- IST-1.F Explain how meiosis results in the transmission of chromosomes from one generation to the next.
- IST-1.G Describe similarities and/ or differences between the phases and outcomes of mitosis and meiosis.
- IST-1.H Explain how the process of meiosis generates genetic diversity.
- IST-1.I Explain the inheritance of genes and traits as described by Mendel’s laws.
- IST-1.J Explain deviations from Mendel’s model of the inheritance of traits.
- EVO-2 Organisms are linked by lines of descent from common ancestry.
- EVO-2.A Explain how shared, conserved, fundamental processes and features support the concept of common ancestry for all organisms.
- SYI-3 Naturally occurring diversity among and between components within biological systems affects interactions with the environment
- SYI-3.B Explain how the same genotype can result in multiple phenotypes under different environmental conditions.
- SYI-3.C Explain how chromosomal inheritance generates genetic variation in sexual reproduction.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Meiosis and the Sexual Life Cycle
- Meiosis is a process that ensures the formation of haploid gamete cells in sexually reproducing diploid organisms—
- a. Meiosis results in daughter cells with half the number of chromosomes of the parent cell.
- b. Meiosis involves two rounds of a sequential series of steps (meiosis I and meiosis II).
- Mitosis and meiosis are similar in the way chromosomes segregate but differ in the number of cells produced and the genetic content of the daughter cells.
- Separation of the homologous chromosomes in meiosis I ensures that each gamete receives a haploid (1n) set of chromosomes that comprises both maternal and paternal chromosomes.
- During meiosis I, homologous chromatids exchange genetic material via a process called “crossing over” (recombination), which increases genetic diversity among the resultant gametes.
- Sexual reproduction in eukaryotes involving gamete formation—including crossing over, the random assortment of chromosomes during meiosis, and subsequent fertilization of gametes—serves to increase variation.
- Errors in mitosis or meiosis can result in changes in phenotype—
- a. Changes in chromosome number often result in new phenotypes, including sterility caused by triploidy, and increased vigor of other polyploids.
- b. Changes in chromosome number often result in human disorders with developmental limitations, including Down syndrome/ Trisomy 21 and Turner syndrome.
Relation Between Genotype and Phenotype
- Segregation, independent assortment of chromosomes, and fertilization result in genetic variation in populations.
- The chromosomal basis of inheritance provides an understanding of the pattern of transmission of genes from parent to offspring.
- Fertilization involves the fusion of two haploid gametes, restoring the diploid number of chromosomes and increasing genetic variation in populations by creating new combinations of alleles in the zygote—
- a. Rules of probability can be applied to analyze passage of single-gene traits from parent to offspring.
- b. The pattern of inheritance (monohybrid, dihybrid, sex-linked, and genetically linked genes) can often be predicted from data, including pedigree, that give the parent genotype/phenotype and the offspring genotypes/phenotypes.
- DNA and RNA are carriers of genetic information.
- Mendel’s laws of segregation and independent assortment can be applied to genes that are on different chromosomes.
- Patterns of inheritance of many traits do not follow ratios predicted by Mendel’s laws and can be identified by quantitative analysis, where observed phenotypic ratios statistically differ from the predicted ratios—
- a. Genes that are adjacent and close to one another on the same chromosome may appear to be genetically linked; the probability that genetically linked genes will segregate as a unit can be used to calculate the map distance between them.
- Some traits are determined by genes on sex chromosomes and are known as sexlinked traits. The pattern of inheritance of sex-linked traits can often be predicted from data, including pedigree, indicating the parent genotype/phenotype and the offspring genotypes/phenotypes.
- Many traits are the product of multiple genes and/or physiological processes acting in combination; these traits therefore do not segregate in Mendelian patterns.
- Some traits result from non-nuclear inheritance—
- a. Chloroplasts and mitochondria are randomly assorted to gametes and daughter cells; thus, traits determined by chloroplast and mitochondrial DNA do not follow simple Mendelian rules.
- b. In animals, mitochondria are transmitted by the egg and not by sperm; as such, traits determined by the mitochondrial DNA are maternally inherited.
- c. In plants, mitochondria and chloroplasts are transmitted in the ovule and not in the pollen; as such, mitochondria-determined and chloroplast-determined traits are maternally inherited.
- Environmental factors influence gene expression and can lead to phenotypic plasticity. Phenotypic plasticity occurs when individuals with the same genotype exhibit different phenotypes in different environments.
- Certain human genetic disorders can be attributed to the inheritance of a single affected or mutated allele or specific chromosomal changes, such as nondisjunction.
Understanding/Key Learning
- The sexual life cycle includes a haploid phase and diploid phase. In most animals (including humans), the predominant phase is diploidy, while haploid gametes are produced solely for the purpose of the production of diploid offspring.
- Sexual reproduction increases genetic variability amongst members of a population, which happens due to several features of the sexual life cycle.
- The process of meiosis carefully separates the chromosomes of a diploid cell into separate gametes, which are each genetically unique from each other and contain only half of the genetic information of the parent cell.
- The process of fertilization restores the diploid number in offspring.
- An organism’s combination of genes (genotype) and environmental factors determines that organism’s physical and physiological characteristics (phenotype). The exact way genes and environment work together to shape phenotype is not fully understood for most traits.
- Different versions of a trait can interact in different ways to produce phenotypes.
- Laws of probability can be used to predict the outcome of specific pairings.
Do
- Relate the terms gene, allele, chromosome, genotype, and phenotype. Understand how various genotypes result in a range of phenotypes.
- Compare and contrast mitosis and meiosis.
- Compare and contrast sexual and asexual life cycles.
- Justify the importance of sexual life cycles for the genetic diversity of a population.
- Model the process of meiosis.
- Predict the outcomes of meiosis in terms of possible gametes produced.
- Relate Mendel’s experiments to the chromosomal model of inheritance.
- Relate Mendel’s laws to the process of meiosis and/or fertilization.
- Predict the outcomes of errors during meiosis, both in terms of nondisjunction and aneuploidies, and in terms of chromosomal rearrangements.
- Interpret karyotypes to determine sex and any chromosomal aberrations.
- Use Punnett Squares to predict expected genotypic and phenotypic ratios in offspring between known matings.
- Distinguish between dominance, codominance, and incomplete dominance. Explain each in terms of their gene expression at the cellular levels.
- Identify human blood types based on antigens, antibodies, and genotypes.
- Use pedigrees to infer inheritance patterns.
- Calculate the chi-square values for the expected and known values of mate pairings; use these values to determine whether or not genes show independent assortment or linkage.
- Produce logical arguments for and against nature and nurture in the debate of “nature versus nurture.”
Unit Essential Questions
Lesson Essential Questions
- How does the process of meiosis result in the production of unique gametes?
- How does sexual reproduction result in increased genetic variability?
- What are Mendel’s Laws? How does each one relate to the process of meiosis and/or to the process of fertilization?
- How can Punnett Squares or other rules of probability to be used predict genotypic and phenotypic ratios from genetic crosses?
- How can alleles interact in an organism to make that organism’s phenotype?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vocabulary
- Abo Blood Types
- Fertilization
- Achondroplasia
- Filial Generations (F1, F2)
- Addition Rule
- Gamete
- Allele
- Gene (Linkage) Mapping
- Aneuploidy
- Genetic Recombination
- Asexual Reproduction
- Genetics
- Autosome
- Genotype
- Barr Bodies
- Germ Cell
- Character
- Haploid
- Chiasma
- Hemizygous
- Clone
- Hemophilia
- Codominance
- Heredity
- Crossing Over
- Heterozygous
- Cystic Fibrosis
- Homologous Chromosomes
- Deletion
- Homozygous
- Dihybrid Cross
- Huntington’s Disease
- Diploid
- Hybrid
- Discrete Characters
- Hybridization
- Dominant
- Incomplete Dominance
- Down Syndrome
- Independent Assortment
- Duchenne Muscular Dystrophy
- Inversion
- Duplication
- Karyotype
- Epistasis
- Law Of Independent Assortment
- Law Of Segregation
- Random Fertilization
- Linked Genes
- Recessive
- Linked Genes
- Recombinant Chromosome
- Locus
- Sex
- Meiosis
- Sex Chromosome
- Meiosis I
- Sex-Linked Gene
- Meiosis Ii
- Sexual Reproduction
- Mendel, Gregor
- Sickle-Cell Disease
- Monohybrid Cross
- Somatic Cell
- Monosomy
- Synapsis
- Multiple Alleles
- Synaptonemal Complex
- Multiplication Rule
- Testcross
- Nondisjunction
- Tetrad
- Normal
- Trait
- P Generation
- Translocation
- Pedigree
- Triploidy
- Phenotype
- Trisomy
- Pleiotropy
- True (Pure) Breeding
- Polygenic Inheritance
- Variation
- Polyploidy
- X Chromosome Inactivation
- Probability
- X-Linked Gene
- Punnett Square
- Zygote
- Quantitative Characters
Assessments
Unit 8: Evolution
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 1.B Explain biological concepts and/or processes.
- 1.C Explain biological concepts, processes, and/ or models in applied contexts.
- 2.A Describe characteristics of a biological concept, process, or model represented visually
- 2.B.a Explain relationships between different characteristics of biological concepts, processes, or models represented visually in theoretical contexts.
- 2.D.c Represent relationships within biological models, including flowcharts.
- 3.B State the null or alternative hypothesis, or predict the results of an experiment
- 3.E.a Propose a new/next investigation based on an evaluation of the evidence from an experiment.
- 4.B.a Describe data from a table or graph, including identifying specific data points.
- 4.B.c Describe data from a table or graph, including describing relationships between variables.
- 5.A.a Perform mathematical calculations, including mathematical equations in the curriculum.
- 6.C: Provide reasoning to justify a claim by connecting evidence to biological theories.
- 6.E.a Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on biological concepts or processes.
- 6.E.b Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on a visual representation of a biological concept, process, or model.
AP Biology Course Content Standards
- SYI-3: Naturally occurring diversity among and between components within biological systems affects interactions with the environment
- SYI-3.A: Explain the connection between variation in the number and types of molecules within cells to the ability of the organism to survive and/or reproduce in different environments.
- SYI-3.D Explain how the genetic diversity of a species or population affects its ability to withstand environmental pressures.
- EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence.
- EVO-1.C Describe the causes of natural selection.
- EVO-1.D Explain how natural selection affects populations.
- EVO-1.E Describe the importance of phenotypic variation in a population.
- EVO-1.F Explain how humans can affect diversity within a population.
- EVO-1.G Explain the relationship between changes in the environment and evolutionary changes in the population.
- EVO-1.H Explain how random occurrences affect the genetic makeup of a population.
- EVO-1.I Describe the role of random processes in the evolution of specific populations.
- EVO-1.J Describe the change in the genetic makeup of a population over time.
- EVO-1.K Describe the conditions under which allele and genotype frequencies will change in populations.
- EVO-1.L Explain the impacts on the population if any of the conditions of HardyWeinberg are not met.
- EVO-1.M Describe the types of data that provide evidence for evolution.
- EVO-1.N Explain how morphological, biochemical, and geological data provide evidence that organisms have changed over time.
- EVO-2 Organisms are linked by lines of descent from common ancestry.
- EVO-2.B Describe the fundamental molecular and cellular features shared across all domains of life, which provide evidence of common ancestry.
- EVO-2.C Describe structural and functional evidence on cellular and molecular levels that provides evidence for the common ancestry of all eukaryotes.
- EVO-3 Life continues to evolve within a changing environment.
- EVO-3.A Explain how evolution is an ongoing process in all living organisms.
- EVO-3.B Describe the types of evidence that can be used to infer an evolutionary relationship.
- EVO-3.C Explain how a phylogenetic tree and/or cladogram can be used to infer evolutionary relatedness.
- EVO-3.D Describe the conditions under which new species may arise.
- EVO-3.E Describe the rate of evolution and speciation under different ecological conditions.
- EVO-3.F Explain the processes and mechanisms that drive speciation.
- EVO-3.G Describe factors that lead to the extinction of a population.
- EVO-3.H Explain how the risk of extinction is affected by changes in the environment.
- EVO-3.I Explain species diversity in an ecosystem as a function of speciation and extinction rates.
- EVO-3.J Explain how extinction can make new environments available for adaptive radiation.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Natural and Artificial Selection
- Natural selection is a major mechanism of evolution.
- According to Darwin’s theory of natural selection, competition for limited resources results in differential survival. Individuals with more favorable phenotypes are more likely to survive and produce more offspring, thus passing traits to subsequent generations.
- Biotic and abiotic environments can be more or less stable/fluctuating, and this affects the rate and direction of evolution; different genetic variations can be selected in each generation.
- Evolutionary fitness is measured by reproductive success.
- Natural selection acts on phenotypic variations in populations.
- Environments change and apply selective pressures to populations.
- Some phenotypic variations significantly increase or decrease fitness of the organism in particular environments.
- Variation at the molecular level provides organisms with the ability to respond to a variety of environmental stimuli.
- Variation in the number and types of molecules within cells provides organisms a greater ability to survive and/or reproduce in different environments.
- Through artificial selection, humans affect variation in other species.
- Convergent evolution occurs when similar selective pressures result in similar phenotypic adaptations in different populations or species.
Evidence of Evolution, Common Ancestry, and Phylogenetics
- Core metabolic pathways are conserved across all currently recognized domains.
- Many fundamental molecular and cellular features and processes are conserved across organisms.
- Evolution is supported by scientific evidence from many disciplines (geographical, geological, physical, biochemical, and mathematical data).
- Molecular, morphological, and genetic evidence from extant and extinct organisms adds to our understanding of evolution—
- a. Fossils can be dated by a variety of methods. These include:
- i. The age of the rocks where a fossil is found
- ii. The rate of decay of isotopes including carbon-14
- iii. Geographical data b. Morphological homologies, including vestigial structures, represent features shared by common ancestry
- A comparison of DNA nucleotide sequences and/or protein amino acid sequences provides evidence for evolution and common ancestry.
- a. Fossils can be dated by a variety of methods. These include:
- Structural and functional evidence supports the relatedness of organisms in all domains.
- Structural evidence indicates common ancestry of all eukaryotes—
- a. Membrane-bound organelles
- b. Linear chromosomes
- c. Genes that contain introns
- Phylogenetic trees and cladograms show evolutionary relationships among lineages—
- a. Phylogenetic trees and cladograms both show relationships between lineages, but phylogenetic trees show the amount of change over time calibrated by fossils or a molecular clock.
- b. Traits that are either gained or lost during evolution can be used to construct phylogenetic trees and cladograms—
- i. Shared characters are present in more than one lineage.
- ii. Shared, derived characters indicate common ancestry and are informative for the construction of phylogenetic trees and cladograms.
- iii. The out-group represents the lineage that is least closely related to the remainder of the organisms in the phylogenetic tree or cladogram.
- c. Molecular data typically provide more accurate and reliable evidence than morphological traits in the construction of phylogenetic trees or cladograms.
- Phylogenetic trees and cladograms can be used to illustrate speciation that has occurred. The nodes on a tree represent the most recent common ancestor of any two groups or lineages.
- Phylogenetic trees and cladograms can be constructed from morphological similarities of living or fossil species and from DNA and protein sequence similarities.
- Phylogenetic trees and cladograms represent hypotheses and are constantly being revised, based on evidence.
Population Genetics & Genetic Equilibrium
- Changes in genotype may affect phenotypes that are subject to natural selection. Genetic changes that enhance survival and reproduction can be selected for by environmental conditions—
- a. The horizontal acquisitions of genetic information primarily in prokaryotes via transformation (uptake of naked DNA), transduction (viral transmission of genetic information), conjugation (cell-to-cell transfer of DNA), and transposition (movement of DNA segments within and between DNA molecules) increase variation.
- b. Related viruses can combine/recombine genetic information if they infect the same host cell.
- c. Reproduction processes that increase genetic variation are evolutionarily conserved and are shared by various organisms.
- Evolution is also driven by random occurrences—
- a. Mutation is a random process that contributes to evolution.
- b. Genetic drift is a nonselective process occurring in small populations—
- i. Bottlenecks.
- ii. Founder effect.
- c. Migration/gene flow can drive evolution.
- Reduction of genetic variation within a given population can increase the differences between populations of the same species.
- Mutation results in genetic variation, which provides phenotypes on which natural selection acts.
- Hardy-Weinberg is a model for describing and predicting allele frequencies in a non-evolving population. Conditions for a population or an allele to be in Hardy-Weinberg equilibrium are—(1) a large population size, (2) absence of migration, (3) no net mutations, (4) random mating, and (5) absence of selection. These conditions are seldom met, but they provide a valuable null hypothesis.
- Allele frequencies in a population can be calculated from genotype frequencies.
- Changes in allele frequencies provide evidence for the occurrence of evolution in a population.
- Small populations are more susceptible to random environmental impact than large populations.
- Populations of organisms continue to evolve.
- All species have evolved and continue to evolve—
- a. Genomic changes over time.
- b. Continuous change in the fossil record.
- c. Evolution of resistance to antibiotics, pesticides, herbicides, or chemotherapy drugs.
- d. Pathogens evolve and cause emergent diseases.
- The level of variation in a population affects population dynamics—
- a. Population ability to respond to changes in the environment is influenced by genetic diversity. Species and populations with little genetic diversity are at risk of decline or extinction.
- b. Genetically diverse populations are more resilient to environmental perturbation because they are more likely to contain individuals who can withstand the environmental pressure.
- c. Alleles that are adaptive in one environmental condition may be deleterious in another because of different selective pressures.
Speciation & Extinction
- Speciation may occur when two populations become reproductively isolated from each other.
- The biological species concept provides a commonly used definition of species for sexually reproducing organisms. It states that species can be defined as a group capable of interbreeding and exchanging genetic information to produce viable, fertile offspring.
- Punctuated equilibrium is when evolution occurs rapidly after a long period of stasis. Gradualism is when evolution occurs slowly over hundreds of thousands or millions of years.
- Divergent evolution occurs when adaptation to new habitats results in phenotypic diversification. Speciation rates can be especially rapid during times of adaptive radiation as new habitats become available.
- Speciation results in diversity of life forms.
- Speciation may be sympatric or allopatric.
- Various prezygotic and postzygotic mechanisms can maintain reproductive isolation and prevent gene flow between populations.
- Extinctions have occurred throughout Earth’s history.
- Extinction rates can be rapid during times of ecological stress.
- Human activity can drive changes in ecosystems that cause extinctions.
- The amount of diversity in an ecosystem can be determined by the rate of speciation and the rate of extinction.
- Extinction provides newly available niches that can then be exploited by different species.
Understanding/Key Learning
- Scientific theories are statements that describe natural phenomena, which have been well-substantiated by evidence and/or experiments, and are widely accepted as the most reasonable and likely explanation for particular phenomena.
- Evolution can be described on the micro- level, where gene pools of a population change, or on the macro- level, where whole species change and/or diverge to make new species.
- The theory of evolution by natural selection and the concept of common ancestry is supported by ample evidence, including homologies and direct evidence.
- Evolution can be measured based on changes to allele frequency and/or phenotypic distributions.
- Evolution accounts for the diversity of all life, as well as for the common features shared by all extinct and extant species.
- Natural selection is the only form of adaptive evolution, but evolution may occur for other reasons.
- Genetic and/or phenotypic variation is necessary for natural selection to occur.
- Traits that increase an individual’s chance of survival and reproduction are adaptations, which will lead to changes in the population.
- Individuals do not evolve.
- Phylogenetic trees and cladograms are diagrams that show the evolutionary relationship of different species.
- Species cannot be easily defined. Biologists usually define species by their ability to reproduce only with members of their own species and not with members of others, but there are many exceptions to this definition.
- Extinction occurs in populations/species that cannot adapt to changes to their environment.
- There have been five major extinction events on Earth. Humans are causing the current (sixth) one.
Do
- Compare and contrast discrete and quantitative characters, using examples.
- Describe views of evolution prior to Darwin, including that of the Classical Greek Philosophers, Carolus Linnaeus, and from the Bible. Describe how each led to or were consequences of the paradigm of the times.
- Describe the factors that influenced Darwin’s understanding of evolution by natural selection, including that of Georges Cuvier, James Hutton and Charles Lyell, Jean-Baptiste Lamarck, Sir Thomas Malthus, and Darwin’s own observations of artificial selection and the specimens collected on his voyages.
- Compare and contrast the proposed theories of evolution by Lamarck and Darwin.
- Outline Darwin’s theory of evolution by natural selection, including the conditions that would allow for it to occur and the mechanism by which populations would change.
- Defend the use of the term “theory” for Darwin’s Theory of Evolution by Natural Selection.
- Analyze evidence that supports Darwin’s claims.
- Relate Darwin’s understanding of populations to genetics.
- Determine whether a population is or is not evolving for a particular trait.
- List the conditions established by Hardy and Weinberg that would result in genetic equilibrium.
- Explain how intrasexual and intersexual selection can impede genetic equilibrium.
- Calculate the allele frequency and phenotypes of a population using the Hardy Weinberg Equation.
- Calculate chi-square to compare the allele frequencies in a Hardy-Weinberg population to actual allele frequencies, and use chi-square to determine whether or not the population is evolving.
- Create cladograms and/or phylogenetic trees based on genetic sequences or phenotypic traits of populations.
- Interpret cladograms and phylogenetic trees.
- Classify a species based on its taxonomic hierarchy.
- Relate taxonomy with phylogeny; explain why there is a discrepancy between these two models of classification.
- Describe the ways that quantitative traits may change in a population, and identify forces that may lead to each type of change.
- Justify the use of the biological species concept.
- Compare and contrast each definition of a species, including the benefits and drawbacks of each and why it is sometimes better to use one concept over another.
- Describe prezygotic and postzygotic barriers that result in reproductive isolation, giving examples of each.
- Describe punctuated equilibrium and gradualism, using evidence from the fossil records to justify or refute these models of evolution.
Unit Essential Questions
Lesson Essential Questions
- What influences led Darwin to develop the theory of evolution by natural selection?
- What evidence supports the theory of evolution by natural selection?
- What are the causes of genetic variability in a population?
- How can Hardy-Weinberg be used to determine if a population is evolving?
- How is evolution measured in quantitative traits?
- How can evolution lead to the formation of new species?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vocabulary
- Acquired Traits
- Disruptive Selection
- Adaptation
- Divergent Evolution
- Adaptive Radiation
- Domains
- Allele Frequency
- Drug Resistance
- Allopatric Speciation
- Embryology
- Analogous Structure
- Endemic Species
- Ancestral Character
- Evolution
- Aristotle
- Fitness
- Artificial Selection
- Fixed Allele
- Behavioral Isolation
- Fossil
- Binomial Nomenclature
- Founder Effect
- Biogeography
- Gametic Isolation
- Bottleneck Effect
- Gene Flow
- Clade
- Gene Pool
- Cladogram
- Genetic Drift
- Conjugation
- Genetic Equilibrium
- Continental Drift
- Genus
- Convergent Evolution
- Geographic Isolation
- Cuvier, Georges
- Gradualism
- Darwin, Charles
- Habitat Isolation
- Derived Character
- Hardy-Weinberg Equation / Equilibrium
- Descent With Modification
- Heterozygous Advantage
- Directional Selection
- Hms Beagle
- Discrete Character
- Homologous Genes
- Homologous Structure
- Post-Zygotic Isolation
- Homology
- Pre-Zygotic Isolation
- Horizontal Gene Transfer
- Punctuated Equilibrium
- Hutton & Lyell
- Qualitative Character
- Hybrid
- Reduced Hybrid Viability
- Ingroup
- Relative Fitness
- Lamarck, Jean-Baptiste
- Scala Naturai
- Linnaeus
- Sexual Dimorphism
- Macroevolution
- Sexual Selection
- Malthus, Thomas
- Sickle Cell Disease
- Mass Extinction
- Speciation
- Maximum Parsimony
- Species
- Microevolution
- Stabilizing Selection
- Molecular Clock
- Sympatric Speciation
- Monophyletic
- Systematics
- Natural Selection
- Taxonomy
- On The Origin Of Species
- Temporal Isolation
- Outgroup
- Theory
- Paleontology
- Transduction
- Paraphyletic
- Transformation
- Phylogenetic Tree
- Use / Disuse
- Phylogeny
- Vestigial Structure
- Polyphyletic
- Wallace, Alfred Russel
Assessments
Unit 9: Ecology
- Standards
- Know
- Understanding/Key Learning
- Do
- Unit Essential Questions
- Lesson Essential Questions
- Materials/Resources
- Vocabulary
- Assessments
Standards
AP Biology Science Practices
- 3.C.a Identify experimental procedures that are aligned to the question, including identifying dependent and independent variables.
- 4.A Construct a graph, plot, or chart.
- 5.A.c Perform mathematical calculations, including rates.
- 5.B Use confidence intervals and/or error bars (both determined using standard errors) to determine whether sample means are statistically different.
- 5.D.a Use data to evaluate a hypothesis (or prediction), including rejecting or failing to reject the null hypothesis.
- 5.D.b Use data to evaluate a hypothesis (or prediction), including supporting or refuting the alternative hypothesis.
- 6.D Explain the relationship between experimental results and larger biological concepts, processes, or theories.
- 6.E.c Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on data.
AP Biology Course Content Standards
- IST-4 The processing of genetic information is imperfect and is a source of genetic variation.
- IST-4.B Explain how alterations in DNA sequences contribute to variation that can be subject to natural selection.
- IST-5 Transmission of information results in changes within and between biological systems.
- IST-5.A Explain how the behavioral responses of organisms affect their overall fitness and may contribute to the success of the population.
- ENE-1 The highly complex organization of living systems requires constant input of energy and the exchange of macromolecules.
- ENE-1.M Describe the strategies organisms use to acquire and use energy.
- ENE-1.N Explain how changes in energy availability affect populations and ecosystems.
- ENE-1.O Explain how the activities of autotrophs and heterotrophs enable the flow of energy within an ecosystem.
- ENE-3 Timing and coordination of biological mechanisms involved in growth, reproduction, and homeostasis depend on organisms responding to environmental cues.
- ENE-3.D Explain how the behavioral and/or physiological response of an organism is related to changes in internal or external environment.
- ENE-4 Communities and ecosystems change on the basis of interactions among populations and disruptions to the environment.
- ENE-4.A Describe the structure of a community according to its species composition and diversity.
- ENE-4.B Explain how interactions within and among populations influence community structure.
- ENE-4.C Explain how community structure is related to energy availability in the environment.
- SYI-1 Living systems are organized in a hierarchy of structural levels that interact.
- SYI-1.G Describe factors that influence growth dynamics of populations.
- SYI-1.H Explain how the density of a population affects and is determined by resource availability in the environment.
- SYI-2 Competition and cooperation are important aspects of biological systems.
- SYI-2.A Explain how invasive species affect ecosystem dynamics.
- SYI-2.B Describe human activities that lead to changes in ecosystem structure and/ or dynamics.
- SYI-2.C Explain how geological and meteorological activity leads to changes in ecosystem structure and/or dynamics.
- SYI-3 Naturally occurring diversity among and between components within biological systems affects interactions with the environment.
- SYI-3.F Describe the relationship between ecosystem diversity and its resilience to changes in the environment.
- SYI-3.G Explain how the addition or removal of any component of an ecosystem will affect its overall short-term and long-term structure.
- EVO-1 Evolution is characterized by change in the genetic make-up of a population over time and is supported by multiple lines of evidence.
- EVO-1.O Explain the interaction between the environment and random or preexisting variations in populations.
PA Reading and Writing in Science and Technical Subjects
- CC.3.6.11-12.H. Draw evidence from informational texts to support analysis, reflection, and research.
- CC.3.5.9-10.C. Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CC.3.6.9-10.B Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
- CC.3.6.9-10.C. Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Know
Behavior
- Organisms respond to changes in their environment through behavioral and physiological mechanisms.
- Organisms exchange information with one another in response to internal changes and external cues, which can change behavior.
- Individuals can act on information and communicate it to others.
- Communication occurs through various mechanisms—
- a. Organisms have a variety of signaling behaviors that produce changes in the behavior of other organisms and can result in differential reproductive success.
- b. Animals use visual, audible, tactile, electrical, and chemical signals to indicate dominance, find food, establish territory, and ensure reproductive success.
- Responses to information and communication of information are vital to natural selection and evolution—
- a. Natural selection favors innate and learned behaviors that increase survival and reproductive fitness.
- b. Cooperative behavior tends to increase the fitness of the individual and the survival of the population.
Ecosystems and the Movement of Matter & Energy
- Organisms use energy to maintain organization, grow, and reproduce—
- a. Organisms use different strategies to regulate body temperature and metabolism.
- i. Endotherms use thermal energy generated by metabolism to maintain homeostatic body temperatures.
- ii. Ectotherms lack efficient internal mechanisms for maintaining body temperature, though they may regulate their temperature behaviorally by moving into the sun or shade or by aggregating with other individuals.
- b. Different organisms use various reproductive strategies in response to energy availability.
- c. There is a relationship between metabolic rate per unit body mass and the size of multicellular organisms—generally, the smaller the organism, the higher the metabolic rate.
- d. A net gain in energy results in energy storage or the growth of an organism.
- e. A net loss of energy results in loss of mass and, ultimately, the death of an organism.
- a. Organisms use different strategies to regulate body temperature and metabolism.
- Changes in energy availability can result in changes in population size.
- Changes in energy availability can result in disruptions to an ecosystem—
- a. A change in energy resources such as sunlight can affect the number and size of the trophic levels.
- b. A change in the producer level can affect the number and size of other trophic levels.
- Autotrophs capture energy from physical or chemical sources in the environment—
- a. Photosynthetic organisms capture energy present in sunlight.
- b. Chemosynthetic organisms capture energy from small inorganic molecules present in their environment, and this process can occur in the absence of oxygen.
- Heterotrophs capture energy present in carbon compounds produced by other organisms.
- a. Heterotrophs may metabolize carbohydrates, lipids, and proteins as sources of energy by hydrolysis.
Population Ecology
- Populations comprise individual organisms that interact with one another and with the environment in complex ways.
- Many adaptations in organisms are related to obtaining and using energy and matter in a particular environment—
- a. Population growth dynamics depend on a number of factors.
- i. Reproduction without constraints results in the exponential growth of a population.
- a. Population growth dynamics depend on a number of factors.
- A population can produce a density of individuals that exceeds the system’s resource availability.
- As limits to growth due to density-dependent and density-independent factors are imposed, a logistic growth model generally ensues.
- The structure of a community is measured and described in terms of species composition and species diversity.
- Communities change over time depending on interactions between populations.
- Interactions among populations determine how they access energy and matter within a community.
- Relationships among interacting populations can be characterized by positive and negative effects and can be modeled. Examples include predator/prey interactions, trophic cascades, and niche partitioning.
- Competition, predation, and symbioses, including parasitism, mutualism, and commensalism, can drive population dynamics.
- Cooperation or coordination between organisms, populations, and species can result in enhanced movement of, or access to, matter and energy.
- An adaptation is a genetic variation that is favored by selection and is manifested as a trait that provides an advantage to an organism in a particular environment.
- Mutations are random and are not directed by specific environmental pressures.
Community Ecology
- Natural and artificial ecosystems with fewer component parts and with little diversity among the parts are often less resilient to changes in the environment.
- Keystone species, producers, and essential abiotic and biotic factors contribute to maintaining the diversity of an ecosystem.
- The diversity of species within an ecosystem may influence the organization of the ecosystem.
- The effects of keystone species on the ecosystem are disproportionate relative to their abundance in the ecosystem, and when they are removed from the ecosystem, the ecosystem often collapses.
- The intentional or unintentional introduction of an invasive species can allow the species to exploit a new niche free of predators or competitors or to outcompete other organisms for resources.
- The availability of resources can result in uncontrolled population growth and ecological changes.
- The distribution of local and global ecosystems changes over time.
- Human impact accelerates change at local and global levels—
- a. The introduction of new diseases can devastate native species.
- b. Habitat change can occur because of human activity
- Geological and meteorological events affect habitat change and ecosystem distribution. Biogeographical studies illustrate these changes.
Understanding/Key Learning
- Just as physical and physiological components are subjected to natural selection, behavior is also integral in the survival and reproduction of a species, and those behaviors are favored by natural selection.
- Population growth is limited by nutrient availability and energy.
- Population growth can be modeled using different equations.
- Populations interact with each other, which establishes community dynamics.
- Anthropogenic consequences to ecosystems include habitat loss and changes, community diversity loss, and ultimately the sixth mass extinction.
Do
- Determine whether behaviors are learned or innate.
- Relate the evolution of populations to their behavioral components.
- Model the movement of matter and energy in ecosystems.
- Relate the matter and energy availability of an ecosystem to the limitations on the number of trophic levels in that ecosystem.
- Model population growth using both the exponential model and the logarithmic model.
- Compare population growth that occurs exponentially to those that occur logarithmically.
- Determine whether limits to population growth are density-dependent or density-independent.
- Relate ecological interactions to evolution, including co-evolution, predator and herbivore adaptations, prey and plant defenses, and diverse mating systems.
Unit Essential Questions
Lesson Essential Questions
- What are the types of innate and learned behaviors?
- How do specific innate and/or learned behaviors lead to increased fitness among members of a population?
- What are the ecological levels of organization?
- Under what conditions can populations grow exponentially? How can these be modeled?
- What factors limit population growth? How can the logistic model be used to estimate the growth rate of a population that is constrained by a carrying capacity?
- How can species of different populations interact?
- How interactions of different populations affect the evolution of those species involved?
Materials/Resources
- College Board AP Biology Resources
- AP Classroom
- Pearson® Mastering Biology (https://mlm.pearson.com/northamerica/)
- Textbook: Urry, Cain, Wasserman, Minorsky; Campbell Biology in Focus (3rd ed.)
- Lab manual: AP® Biology Investigative Labs: An Inquiry-Based Approach, 2019
- Online resources - Gizmos, HHMI, others as needed
- Other relevant materials as needed
Vocabulary
- Abiotic Factor
- Decomposer
- Agonistic Behavior
- Demography
- Altruism
- Density
- Aposematic Coloration
- Density Dependent Factor
- Aquatic Biome
- Density Independent Factor
- Arid
- Detritus
- Associative Learning
- Detritivore
- Batesian Mimicry
- Dispersal
- Behavioral Ecology
- Disturbance
- Biogeochemical Cycle
- Diversity Index
- Biomanipulation
- Ecological Succession
- Biomass
- Ecosystem
- Biomass Pyramid
- Ecosystem Engineers
- Biome
- Endangered Species
- Bioremediation
- Eutrophication
- Biotic Factor
- Evapotranspiration
- Carbon Cycle
- Exploitation
- Carrying Capacity
- Exponential Growth Model
- Certainty Of Paternity
- Fixed Action Pattern
- Character Displacement
- Food Chain
- Circadian
- Food Web
- Circannual
- Foraging
- Climate
- Foundation Species
- Climate Change
- Gross Primary Production
- Coefficient Of Relatedness
- Hamilton’s Rule
- Cognition
- Herbivory
- Cohort
- Immigration, Emigration
- Commensalism
- Imprinting
- Communication
- Inclusive Fitness
- Community
- Innate Behavior
- Competition
- Intersexual Selection
- Culture
- Interspecific Interaction
- Population Dynamics
- Intrasexual Selection
- Predation
- Intraspecific Interaction
- Primary Consumer
- Intrinsic Rate Of Increase
- Primary Producer
- Introduced Species
- Primary Production
- Keystone Species
- Production Efficiency
- Kin Selection
- Promiscuous
- Law Of Conservation Of Energy
- Proximate Cause
- Law Of Conservation Of Mass
- Relative Abundance
- Learned Behavior
- Resource Partitioning
- Learning
- Seasonality
- Life History
- Secondary Production
- Life Table
- Sexual Dimorphism
- Limiting Nutrient
- Sexual Selection
- Logistic Growth Model
- Sign Stimulus
- Metapopulation
- Signal
- Migration
- Social Learning
- Monogamy
- Species Diversity
- Muellerian Mimicry
- Species Richness
- Mutualism
- Survivorship (Curve)
- Net Primary Production
- Symbiosis
- Niche
- Terrestrial Biome
- Nitrogen Cycle
- Territoriality
- Ocean Current
- Tinbergen, Niko
- Parasitism
- Trophic Efficiency
- Parental Care
- Trophic Level
- Pathogen
- Trophic Structure
- Pheromones
- Tropical
- Phosphorus Cycle
- Ultimate Cause
- Polar
- Vector
- Polygamy
- Vertical Layering