College Board AP Biology Exam Notes

College Board AP® Biology Section I: Multiple Choice (Set B)

Overview of the Exam

  • Date: Monday, April 20, 2026
  • Time: 1 hour 30 minutes
  • Total Marks: /67
Instructions
  • Complete the mock exam paper in one sitting under exam conditions.
  • Utilize all available time and check answers before submission.
  • This is a practice exam; mistakes are acceptable and beneficial for improvement.
Required Materials
  • Items necessary for the exam:
      - Scientific calculator (as appropriate)
      - Pencil
      - Black ink or black ball-point pen

Structure of the Exam

  • The exam contains 60 questions total.
  • Mark your responses electronically via provided scanning or online options.

Content Breakdown

Question 1
  1. Water Molecule Composition and Bonding
       - Water is composed of hydrogen and oxygen atoms.
       - Bonds:
         - Covalent Bonds: Hold hydrogen and oxygen together within a water molecule.
         - Hydrogen Bonds: Occur between water molecules; illustrated by dashed lines in models.
       - Impact of Hydrogen Bonding:
         - Affects properties such as surface tension.
         - Biological implications:
           - Influences water transport in plants.
           - Affects movement of organisms in aquatic environments.
       - Explain Polarity and Hydrogen Bonding:
         - Polarity arises from the unequal sharing of electrons between hydrogen and oxygen, leading to partial charges and hydrogen bonding capability.
Question 2
  1. Effect of Temperature on Water Surface Tension
       - Investigative Study: Analyzed surface tension of water at varying temperatures outlined in Table 1.
       - Table 1 Data:
         | Temperature (°C) | Surface Tension (mN/m) |
         |------------------|------------------------|
         | 5 | 75.6 |
         | 10 | 74.2 |
         | 20 | 72.8 |
         | 30 | 71.2 |
         | 40 | 69.6 |
       - Graph Construction:
         - Required an appropriately labeled graph based on the temperature and surface tension data.
Question 3
  1. Phosphorus in Biological Processes
       - Role of Phosphorus:
         - Essential for building biological molecules in cells.
       - Impact of Decreased Phosphorus Availability on ATP Production:
         - Predictable decline in ATP production if phosphorus is limited.
       - Affected Cellular Processes:
         - One example is cellular respiration, where ATP generation relies heavily on phosphorus-containing compounds.
       - Phosphorus in Lipid Function:
         - Structural role in phospholipid composition essential for cell membranes.
         - Location of Lipids in Eukaryotic Cells:
           - Present in cellular membranes, especially in structures like the phospholipid bilayer.
Question 4
  1. Cellulose Structure and Biological Significance
       - Key Component: Cellulose strengthens plant cell walls.
       - Bonding in Cellulose Formation:
         - Monomer units bound by C-C covalent bonds.
         - Also features hydrogen bonds between adjacent chains for rigidity.
Question 5
  1. Amino Acids and Protein Synthesis
       - R Groups of Amino Acids:
         | Amino Acid | R Group |
         |----------------|---------------------------------|
         | Alanine | CH3 |
         | Asparagine | CH2CONH2 |
         | Aspartic acid | CH(COOH) |
         | Glutamic acid | CH2CH(COOH) |
         | Glycine | H |
         | Serine | CH2OH |
       - Polypeptide Identification:
         - Analyze structural composition based on R groups to identify amino acids forming a given polypeptide structure illustrated in Figure 1.
Question 6
  1. Phospholipid Composition in Bacterial Membranes
       - Comparison of Three Bacterial Samples:
         | Bacteria Sample | % Saturated Fatty Acids | % Unsaturated Fatty Acids |
         |----------------|-------------------------|---------------------------|
         | A | 82 | 18 |
         | B | 25 | 75 |
         | C | 55 | 45 |
       - Conclusions Supported by Data:
         - Key effects on membrane fluidity derived from varying saturation levels of fatty acids across environments.
Question 7
  1. Insulin Production and Role of Rough Endoplasmic Reticulum (RER)
       - Hypothesis Testing:
         - Experiments disrupting the rough ER while measuring resultant insulin levels can best test the hypothesis regarding its role in production.
Question 8
  1. Gill Surface Area Adaptations in Fish
       - Investigative Study on Environmental Factors:
         - Data shows correlation between fish body mass and gill surface area across different oxygen levels (normoxia/hyperoxia).
Question 9
  1. Photosynthesis and Chloroplast Function in Algae
       - Structure of Algal Chloroplasts:
         - Composed of stroma, thylakoids, and grana.
       - Light-Dependent and Independent Reactions:
         - Correct identification of where photosynthetic processes occur.
Additional Questions
  • The document continues with further investigation into enzyme functions, metabolic processes, signaling pathways, and genetic inheritance.
Summary of Key Concepts
  • Formative biology concepts outlined in questions include:
      - The importance of molecular structures and bonds in biological systems.
      - The physiological and environmental adaptations of organisms.
      - Role of enzymes and metabolic pathways in maintaining life processes.
      - Significance of genetic variations as they relate to evolutionary biology.
Conclusion
  • This detailed outline covers a wide range of biological principles critical for AP Biology exam preparation, with a focus on understanding and applying complex concepts under exam conditions.