AP Biology Exam Review Notes

Exam Information

Exam Date & Time: Monday, May 5th, 2025 @ 8:00 AM
Materials are constructed using the 2020 CED, 2013 Practice Exam, 2015 CED, released FRQ questions, and self-created questions.
Organized with the standards from the CED (Course and Exam Description) followed by questions designed to refresh memory on the topics.
Topics may repeat due to overlapping standards.
This review material is not associated with AP/CollegeBoard.
Multiple choice questions come with an explanations section.

AP Review Schedule - February 2025

Week 1:
- 2/3: 1.5
- 2/4: 1.6
- 2/5: MCQ Practice
- 2/6: BREAK
- 2/7: 2.1
- 2/8: 2.2
Week 2:
- 2/9: 2.3
- 2/10: 2.4
- 2/11: 2.5
- 2/12: 2.6
- 2/13: 2.7
- 2/14: 2.8
- 2/15: 2.9
Week 3:
- 2/16: 2.10
- 2/17: 2.11
- 2/18: MCQ Practice
- 2/19: FRQ Practice
- 2/20: FRQ Practice
- 2/21: BREAK
- 2/22: 3.1
Week 4:
- 2/23: 3.2
- 2/24: 3.3
- 2/25: 3.4
- 2/26: 3.5
- 2/27: 3.6
- 2/28: 3.7

AP Review Schedule - March 2025

Week 1:
- 3/1: MCQ Practice
- 3/2: FRQ Practice
- 3/3: FRQ Practice
- 3/4: BREAK
- 3/5: 4.1
- 3/6: 4.2
- 3/7: 4.3
Week 2:
- 3/8: 4.4
- 3/10: 4.6
- 3/11: 4.7
- 3/12: MCQ Practice
- 3/13: FRQ Practice
- 3/14: FRQ Practice
- 3/15: BREAK
Week 3:
- 3/16: 5.1
- 3/17: 5.2
- 3/18: 5.3
- 3/19: 5.4
- 3/20: 5.5
- 3/21: 5.6
- 3/22: MCQ Practice
Week 4:
- 3/23: FRQ Practice
- 3/24: FRQ Practice
- 3/25: BREAK
- 3/26: 6.1
- 3/27: 6.2
- 3/28: 6.3
- 3/29: 6.4
- 3/30: 6.5
- 3/31: 6.6

AP Review Schedule - April 2025

Week 1:
- 4/1: 6.7
- 4/2: 6.8
- 4/3: MCQ Practice
- 4/4: FRQ Practice
- 4/5: FRQ Practice
- 4/6: BREAK
- 4/7: 7.1
Week 2:
- 4/8: 7.2
- 4/9: 7.3
- 4/10: 7.4
- 4/11: 7.5
- 4/12: 7.6
- 4/13: 7.7
- 4/14: 7.8
Week 3:
- 4/15: 7.9
- 4/16: 7.10
- 4/17: 7.11
- 4/18: 7.12
- 4/19: 7.13
- 4/20: MCQ Practice
- 4/21: FRQ Practice
Week 4:
- 4/22: FRQ Practice
- 4/23: BREAK
- 4/24: 8.1
- 4/25: 8.2
- 4/26: 8.3
- 4/27: 8.4
- 4/28: 8.5
- 4/29: 8.6
- 4/30: 8.7

Science Practices for AP Biology Exam

1 – Concept Explanation: Explain biological concepts, processes, and models presented in written format.
- 1.A – Describe biological concepts and/or processes.
- 1.B – Explain biological concepts and/or processes.
- 1.C – Explain biological concepts, processes, and/or models in applied contexts.
2 – Visual Representation: Analyze visual representations of biological concepts and processes.
- 2.A – Describe characteristics of a biological concept, process, or model represented visually.
- 2.B – Explain relationships between different characteristics of biological concepts, processes, or models represented visually.
  - a. In theoretical contexts.
  - b. In applied contexts.
- 2.C – Explain how biological concepts or processes represented visually relate to larger biological principles, concepts, processes, or theories.
- 2.D – Represent relationships within biological models, including:
  - a. Mathematical models.
  - b. Diagrams.
  - c. Flow charts.
3 – Questions and Methods: Determine scientific questions and methods.
- 3.A – Identify or pose a testable question based on an observation, data, or a model.
- 3.B – State the null or alternative hypotheses, or predict the results of an experiment.
- 3.C – Identify experimental procedures that are aligned to the question, including:
  - a. Identifying dependent and independent variables.
  - b. Identifying appropriate controls.
  - c. Justifying appropriate controls.
- 3.D – Make observations, or collect data from representations of laboratory setups or results. (Lab only; not assessed)
- 3.E – Propose a new/next investigation based on:
  - a. An evaluation of the evidence from an experiment.
  - b. An evaluation of the design/methods.
4 – Representing and Describing Data: Represent and describe data.
- 4.A – Construct a graph, plot, or chart (X,Y; Log Y; Bar; Histogram; Line, Dual Y; Box and Whisker; Pie).
  - a. Orientation
  - b. Labeling
  - c. Units
  - d. Scaling
  - e. Plotting
  - f. Type
  - g. Trend line
- 4.B – Describe data from a table or graph, including:
  - a. Identifying specific data points.
  - b. Describing trends and/or patterns in the data.
  - c. Describing relationships between variables.
5 – Statistical Tests and Data Analysis: Perform statistical tests and mathematical calculations to analyze and interpret data.
- 5.A – Perform mathematical calculations, including:
  - a. Mathematical equations in the curriculum.
  - b. Means.
  - c. Rates.
  - d. Ratios.
  - e. Percentages.
- 5.B – Use confidence intervals and/or error bars (both determined using standard errors) to determine whether sample means are statistically different.
- 5.C – Perform chi-square hypothesis testing.
- 5.D – Use data to evaluate a hypothesis (or prediction), including:
  - a. Rejecting or failing to reject the null hypothesis.
  - b. Supporting or refuting the alternative hypothesis.
6 – Argumentation: Develop and justify scientific arguments using evidence
- 6.A – Make a scientific claim.
- 6.B – Support a claim with evidence from biological principles, concepts, processes, and/or data.
- 6.C – Provide reasoning to justify a claim by connecting evidence to biological theories.
- 6.D – Explain the relationship between experimental results and larger biological concepts, processes, or theories.
- 6.E – Predict the causes or effects of a change in, or disruption to, one or more components in a biological system based on:
  - a. Biological concepts or processes.
  - b. A visual representation of a biological concept, process, or model.
  - c. Data.

Exam Strategies

Underline important words in the question or prompt.
Jot down notes to help answer the question.
Cover answer choices and develop your own answer to avoid distractions.
Use figures or diagrams to aid in answering questions.
Annotate graphs and show work on math problems.
Time management: 1.5 min/MCQ (watch clock for 10 min/15 Qs).
Read the question multiple times.
Label responses (a), (b), (c) & (d).
Answer in knowledge order.
Do not restate the question.
Additional examples are not scored; clearly denote "the first", "the second", etc."
Beware of contradictions.
Use diagrams.
Define terms.
Graphs: correct type, scale, and labels.
Write clearly and legibly.
Cross out responses not to be scored with a single line.
Use pen for FRQs (but graph in pencil).
Avoid writing utensils that bleed or smudge.
Time management: 5 min read & renumber, 20 min/long, 8 min/short.
If you accidentally respond on the wrong question page, leave a note on the corect page (i.e. "see Q#2"). DO NOT RE-WRITE RESPONSE.

Topic Review - Unit 1: Chemistry of Life

1.1: Structure of Water and Hydrogen Bonding
1.2: Elements of Life
1.3: Introduction to Biological Macromolecules
1.4: Properties of Biological Macromolecules
1.5: Structure and Function of Biological Macromolecules
1.6: Nucleic Acid
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 2: Cell Structure and Function

2.1: Cell Structure: Subcellular Components
2.2: Cell Structure and Function
2.3: Cell Size
2.4: Plasma Membranes
2.5: Membrane Permeability
2.6: Membrane Transport
2.7: Facilitated Diffusion
2.8: Tonicity and Osmoregulation
2.9: Mechanisms of Transport
2.10: Compartmentalization
2.11: Origins of Cell Compartmentalization
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 3: Cellular Energetics

3.1: Enzyme Structure
3.2: Enzyme Catalysis
3.3: Environmental Impacts on Enzyme Function
3.4: Cellular Energy
3.5: Photosynthesis
3.6: Cellular Respiration
3.7: Fitness
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 4: Cell Communication and Cell Cycle

4.1: Cell Communication
4.2: Introduction to Signal Transduction
4.3: Signal Transduction
4.4: Changes in Signal Transduction Pathways
4.5: Feedback
4.6: Cell Cycle
4.7: Regulation of Cell Cycle
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 5: Heredity

5.1: Meiosis
5.2: Meiosis and Genetic Diversity
5.3: Mendelian Genetics
5.4: Non-Mendelian Genetics
5.5: Environmental Effects on Phenotype
5.6: Chromosomal Inheritance
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 6: Gene Expression and Regulation

6.1: DNA and RNA Structure
6.2: Replication
6.3: Transcription and RNA Processing
6.4: Translation
6.5: Regulation of Gene Expression
6.6: Gene Expression and Cell Specialization
6.7: Mutations
6.8: Biotechnology
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 7: Natural Selection

7.1: Introduction to Natural Selection
7.2: Natural Selection
7.3: Artificial Selection
7.4: Population Genetics
7.5: Hardy-Weinberg Equilibrium
7.6: Evidence of Evolution
7.7: Common Ancestry
7.8: Continuing Evolution
7.9: Phylogeny
7.10: Speciation
7.11: Extinction
7.12: Variation in Populations
7.13: Origin of Life on Earth
Multiple Choice Practice
Free Response Practice

Topic Review - Unit 8: Ecology

8.1: Responses to the Environment
8.2: Energy Flow Through Ecosystems
8.3: Population Ecology
8.4: Effect of Density of Populations
8.5: Community Ecology
8.6: Biodiversity
8.7: Disruptions to Ecosystems
Multiple Choice Practice
Free Response Practice

Unit 1: Chemistry of Life

1.1 Structure of Water
- Learning Objective SYI-1.A: Explain how the properties of water that result from its polarity and hydrogen bonding affect its biological function.
1.2 Elements of Life
- Learning Objective ENE-1.A: Describe the composition of macromolecules required by living organisms.
1.3 Introduction of Biological Macromolecules
- Learning Objective SYI-1.B: Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
1.4 Properties of Biological Macromolecules
- Learning Objective SYI-1.B: Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
1.5 Structure and Function of Biological Macromolecules
- Learning Objective SYI-1.C: Explain how a change in the subunits of a polymer may lead to changes in structure or function of the macromolecule.
1.6 Nucleic Acids
- Learning Objective IST-1.A: Describe the structural similarities and differences between DNA and RNA.

Topic 1.1: Structure of Water and Hydrogen Bonding

Learning Objective SYI-1.A: Explain how the properties of water that result from its polarity and hydrogen bonding affect its biological function.
- I can describe a hydrogen bond.
- I can explain how two strands of DNA bind to create the double helix.
- I can explain ways that R groups affect the structure of a protein.
- I can identify the properties of water caused by hydrogen bonds.
- I can explain what makes water polar.
- I can explain what moves water against gravity up a capillary tube.
- I can explain what allows a water strider to walk on water.
Key questions:
- What is a hydrogen bond?
- Where are hydrogen bonds found in water?
- Where are hydrogen bonds found in DNA?
  - How many hydrogen bonds are found between each complementary base pairing?
- What is the structure of an amino acid?
  - What are the three options for the R group?
  - For each R group option, describe the polarity and justify your response.
- What are three properties of water?
  - How did hydrogen bonding allow for each property?
- Describe why water is considered a polar molecule?
- Using the properties of water, describe how water can move up a capillary tube to move from the roots to the leaves in a plant.
- Using the properties of water, describe how a water strider can walk on water.

Topic 1.2: Elements of Life

Learning Objective ENE-1.A: Describe the composition of macromolecules required by living organisms.
*I can identify the macromolecules required by living organisms.
*I can describe the function of proteins in living organisms.
*I can describe the function of lipids in living organisms.
*I can describe the function of carbohydrates in living organisms.
*I can describe the function of nucleic acids in living organisms.
*I can describe how the R group affects the folding of a protein.
*I can identify the elements found in carbohydrates.
*I can identify the elements found in proteins.
*I can identify the elements found in nucleic acids.
*I can identify the elements found in lipids.
*I can describe how macromolecules are formed.
*I can describe how macromolecules are broken down.
*I can identify which macromolecules contain nitrogen.
*I can identify which macromolecules contain phosphorus.
*I can identify which macromolecules contain sulfur.
Key questions:
- What are the four macromolecules?
- What are the elements found in a carbohydrate?
- What are three functions of carbohydrates in living organisms?
- What are the elements found in a protein?
  - What are the functional groups found in all amino acids?
- What are three functions of proteins in living organisms?
- What are the elements found in nucleic acids?
  - What are parts found in all nucleotides?
- What are three functions of nucleic acids in living organisms?
- What are the elements found in a lipid?
  - How are the three different types of lipids different?
- What are three functions of lipids in living organisms?
- Which macromolecule(s) contain nitrogen?
- Which macromolecule(s) contain phosphorus?
- Which macromolecule(s) contain sulfur?
- How does the R group affect the folding of the protein? (include polar and nonpolar R groups)
- What is dehydration?
  - Provide an example of dehydration.
- What is hydrolysis?
  - Provide an example of hydrolysis.

Topic 1.3: Introduction to Biological Macromolecules

Learning Objective SYI-1.B: Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
- I can describe the process of hydrolysis.
- I can describe the process of dehydration.
- I can identify the bond between carbohydrate monomers.
- I can identify the bond between protein monomers.
- I can identify the bond between nucleic acid monomers.
Key questions:
- What is the hydrolysis?
  - Identify inputs and outputs using a specific example.
- What is the dehydration?
  - Identify inputs and outputs using a specific example.
- What type of bond is found in carbohydrates?
  - Specifically, where is this bond located?
- What type of bond is found between protein monomers?
  - Specifically, where is this bond located?
- What type of bond is found between nucleic acid monomers?
  - Specifically, where is this bond located?

Topic 1.4: Properties of Biological Macromolecules

Learning Objective SYI-1.B: Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
- I can describe the structural components of the monomer of a carbohydrate.
- I can describe the structural components of the monomer of a protein.
- I can describe the structural components of the monomer of a nucleic acid.
- I can describe the structural components of a phospholipid.
- I can describe the difference between the bonds of starch and cellulose.
- I can describe the structural differences between DNA and RNA.
- I can identify an R group as hydrophobic, hydrophilic, or ionic.
- I can describe the effect of level of saturation on function of lipids.
Key questions:
- What is the monomer of a carbohydrate?
  - Identify the components of the monomer.
- What is the monomer of a protein?
  - Identify the components of the monomer.
- What is the monomer of a nucleic acid?
  - Identify the components of the monomer.
- Identify the components of a phospholipid.
- Starch vs. Cellulose
  - What type of bond is found in starch?
  - What type of bond is found in cellulose?
  - Which bond can be broken by animals?
- Compare and contrast DNA and RNA using the following chart:
  - DNA
    - Pentose Sugar
    - Nitrogenous Bases
    - Strandedness (traditionally)
  - RNA
    - Pentose Sugar
    - Nitrogenous Bases
    - Strandedness (traditionally)
- Identify the group as hydrophobic, hydrophilic, or charged?
- How does a saturated and unsaturated fatty acid differ?
  - How does the level of saturation affect the function of the lipid?

Topic 1.5: Structure and Function of Biological Macromolecules

Learning Objective SYI-1.C: Explain how a change in the subunits of a polymer may lead to changes in structure or function of the macromolecule.
- I can explain how changes in the subunits of a protein may lead to changes in structure.
- I can explain how changes in the subunits of a protein may lead to changes in function.
- I can explain how changes in the subunits of a nucleic acid may lead to changes in structure.
- I can explain how changes in the subunits of a nucleic acid may lead to changes in function.
- I can describe the directionality of a nucleic acid.
- I can describe the directionality of a protein.
- I can identify the appropriate base pairing based on Chargaff’s rules.
- I can identify the location of a growing nucleic acid strand.
- I can describe the levels of folding found in a protein.
- I can describe the structure of carbohydrate polymers.
- I can describe the structure of nucleic acid polymers.
- I can describe the structure of protein polymers.
- I can describe the structure of a fat.
- I can describe the structure of a phospholipid.
- I can describe the structure of a steroid.
Key questions:
- Describe how a nonpolar to polar R group substitution changes the structure and function of a protein.
- Describe how a cytosine to thymine substitution changes the structure and function of DNA.
  - Note this is a pyrimidine-to-pyrimidine substitution
- Describe how a cytosine to guanine substitution changes the structure and function of DNA.
  - Note this is a pyrimidine-to-purine substitution
- Describe how a deoxyribose to ribose changes the structure and function of a nucleic acid.
- Describe the structure of the nucleic acid polymer.
  - What are the ends called and what is found at each end?
  - Which end is the location of the growing nucleic acid strand?
- What are the complementary base pairings found in nucleic acids?
  - Identify the number of hydrogen bonds found between these two nitrogenous bases.
- Use the following chart to describe the levels of folding found in proteins.
  - Level of Folding
    - Description
    - Types of Bonds
  - Primary
    - Description
    - Types of Bonds
  - Secondary
    - Description
    - Types of Bonds
  - Tertiary
    - Description
    - Types of Bonds
  - Quaternary
    - Description
    - Types of Bonds
- What are the ends of a protein called and what is found at each end?
  - Which end is the location of the growing polypeptide strand?
- Describe the structure of a carbohydrate polymer.
- What are the components of a fat molecule?
- What are the components of a phospholipid?
- Describe the structure of a steroid.

Topic 1.6: Nucleic Acid

Learning Objective IST-1.A: Describe the structural similarities and differences between DNA and RNA.
- I can describe the structure of DNA
- I can describe the structure of RNA
- I can describe the structural similarities between DNA and RNA
- I can describe the sugar differences between DNA and RNA
- I can describe the nitrogenous base differences between DNA and RNA
- I can describe the structural differences between polymers of DNA and RNA
- I can describe the structural differences between directionality of DNA and RNA
Key questions:
- What are the three components of a DNA or RNA molecule?
- Identify differences between DNA and RNA using the following chart:
  - DNA
    - Pentose Sugar
    - Nitrogenous Base Difference
    - Strandedness (traditionally)
    - Directionality
  - RNA
    - Pentose Sugar
    - Nitrogenous Base Difference
    - Strandedness (traditionally)
    - Directionality

Multiple Choice Practice - Unit 1

Scientists examined the folded structure of a purified protein resuspended in water and found that amino acids with nonpolar R groups were primarily buried in the middle of the protein, whereas amino acids with polar R groups were primarily on the surface of the protein. Which of the following best explains the location of the amino acids in the folded protein?
- a. Polar R groups on the surface of the protein can form ionic bonds with the charged ends of the water molecules.
- b. Polar R groups are too bulky to fit in the middle of the protein and are pushed toward the protein’s surface.
- c. Nonpolar R groups that cannot form hydrogen bonds with water are pushed into the middle of the protein.
- d. Nonpolar R groups from different parts of the protein form covalent bonds with each other to maintain the protein’s structure.
Rosalind Franklin’s x-ray diffraction images taken in the 1950s most directly support which of the following claims about DNA?
- a. The ratios of base pairs are constant.
- b. The nucleotide sequence determines genetic information.
- c. The two strands of DNA are antiparallel.
- d. The basic molecular structure is a helix.
Which of the following does not result from hydrogen bonding in water molecules?
- a. Cohesion
- b. Adhesion
- c. Surface Tension
- d. Dissolving fats
Why is water considered polar?
- a. Nonpolar covalent bonds in structure
- b. Ionic bonds in structure
- c. Polar covalent bonds in structure
- d. Hydrophobic interaction in structure
Which macromolecule(s) have nitrogen?
- a. Carbohydrates
- b. Proteins
- c. Nucleic Acids
- d. Nucleic Acids & Proteins
Which macromolecule(s) have phosphorus?
- a. Carbohydrates
- b. Proteins
- c. Nucleic Acids
- d. Fats
Which macromolecule(s) have sulfur?
- a. Carbohydrates
- b. Proteins
- c. Nucleic Acids
- d. Fats
Describes the forming of a bond between monomers with the removal of a water molecule.
- a. Hydrolysis
- b. Dehydration
Describes the breaking of a bond within a polymer using water.
- a. Hydrolysis
- b. Dehydration
Which of the following is NOT in the monomer of a nucleic acid?
- a. pentose sugar
- b. nitrogenous base
- c. phosphate
- d. amino acid
Which of the following is NOT in the monomer of a protein?
- a. Amine Group
- b. R Group
- c. Carboxyl Group
- d. Nitrogenous Base
Describe the orientation of the phospholipids in the membrane.
- a. Phospholipids orient in bilayer with hydrophilic heads on exterior
- b. Phospholipids orient in monolayer with hydrophilic head on extracellular
- c. Phospholipids orient in bilayer with hydrophobic tails on exterior
- d. Phospholipids orient in monolayer with hydrophobic tails on extracellular
How is DNA/RNA synthesis directionally oriented?
- a. new nucleotides are added to 5' phosphate
- b. new nucleotides are added to 3' phosphate
- c. new nucleotides are added to 5' hydroxyl
- d. new nucleotides are added to 3' hydroxyl
Identify the pairing and number of bonds in DNA double helix
- a. A pairs with T (2 bonds) & G pairs with C (3 bonds)
- b. A pairs with G (2 bonds) & T pairs with C (3 bonds)
- c. A pairs with T (3 bonds) & G pairs with C (2 bonds)
- d. A pairs with G (3 bonds) & T pairs with C (2 bonds)
What component of the polypeptide is the next amino acid added forming the peptide bond?
- a. amino group
- b. hydrogen
- c. carboxyl group
- d. R group
Which protein involves R group bonding to form the final three-dimensional structure?
- a. primary
- b. secondary
- c. tertiary
- d. quaternary
Which protein structure involves the peptide bonds between amino acids?
- a. primary
- b. secondary
- c. tertiary
- d. quaternary
DNA and RNA differ on many qualities, which of the following is NOT a difference?
- a. Sugar
- b. Nitrogenous Base
- c. Phosphate Group
- d. Strandedness

Multiple Choice Key & Explanations - Unit 1

1 C. Nonpolar R groups that cannot form hydrogen bonds with water are pushed into the middle of the protein. 1.4 2020 CED #12
2 D. The basic molecular structure is a helix. 1.5 2013 #6
3 D. Dissolving fats 1.1 Self
4 C. Polar covalent bonds in structure 1.1 Self
5 D. Nucleic Acids & Proteins 1.2 Self
6 C. Nucleic Acids 1.2 Self
7 B. Proteins 1.2 Self
8 B. Dehydration 1.3 Self
9 A. Hydrolysis 1.3 Self
10 D. Amino Acid 1.4 Self
11 D. Nitrogenous Base 1.4 Self
12 A. Phospholipids orient in bilayer with hydrophilic heads on exterior 1.4 Self
13 D. new nucleotides are added to 3' hydroxyl 1.5 Self
14 A. A pairs with T (2 bonds) & G pairs with C (3 bonds) 1.5 Self
15 C. carboxyl group 1.5 Self
16 C. tertiary 1.5 Self
17 A. primary 1.5 Self
18 C. Phosphate Group 1.6 Self
1 Explanation:
- A Polar groups are formed from polar covalent bonding (unequal sharing of electrons) which gives the polar groups a partial charge. An ionic bond is the attractive bond between an cation and an anion which result from the loss or gain of an electron.
- B Polar groups will be attracted to the polar nature of water resulting in the polar groups on the surface of the protein.
- C Nonpolar groups are formed from nonpolar covalent bonding (equal sharing of electrons) which results in no partial charge. The absence of the partial charge inhibits the hydrogen bonding with water molecules which are polar.
- D Bonding (including covalent) between R groups will allow for covalent bonding (and other