ADVANCED PLACEMENT · COLLEGE BOARD STYLE
AP Biology Exam A+
2026/2027 Official Exam
AP Exam with Questions & Verified Answers 2026/2027
60 Multiple-Choice Questions · Units 1–8 · Application & Analysis Level
A+ QUESTIONS 4 SECTIONS 100%
VERIFIED COVERED RATIONALES
CATEGORIES
■ Chemistry of Life & Cell Structure/Function
■ Cellular Energetics & Cell Communication/Cycle
■ Heredity & Gene Expression/Regulation
■ Natural Selection & Ecology
Examination Specifications
Difficulty: Advanced Placement · Bloom’s: Application / Analysis
Question Format: Multiple Choice (A–D) · Marks: 1 per question
Passing Score: 70% (approx; scaled 1–5, 3+ considered passing) · Total Marks: 60
Content Alignment
This examination is aligned to the publicly available College Board AP Biology Course and Exam Description, covering the chemistry of life, cell
structure and function, cellular energetics, cell communication and the cell cycle, heredity, gene expression and regulation, natural selection, and
ecology.
STUVIAACTUALEXAM
, Section 1: Chemistry of Life & Cell Structure/Function
Q1.
A researcher places a sample of pure phospholipid molecules in water and observes that they spontaneously form bilayers. This behavior is
best explained by the fact that phospholipids are:
A. Amphipathic, with hydrophobic fatty-acid tails that cluster away from water and hydrophilic heads that interact with water
B. Entirely hydrophilic and dissolve completely in water
C. Composed only of saturated fatty acids that solidify at room temperature
D. Unable to form any ordered structure without enzymatic catalysis
Correct Answer: A
Rationale: Phospholipids have hydrophilic phosphate heads and hydrophobic tails. In aqueous environments the tails aggregate inward while heads face
water, producing bilayers—the foundation of cellular membranes.
Q2.
An enzyme-catalyzed reaction proceeds rapidly at pH 7 but slows dramatically at pH 3. The most likely explanation is that the low pH:
A. Increases the activation energy of the reaction beyond any recoverable level
B. Converts the substrate into an entirely different molecule that can never bind
C. Permanently destroys all peptide bonds in the enzyme
D. Alters the ionization of amino-acid side chains, disrupting the enzyme’s active-site shape and substrate binding
Correct Answer: D
Rationale: Extreme pH changes the charge state of critical residues, distorting tertiary structure and the active site so that catalysis is impaired; many such
changes are reversible if conditions are restored.
Q3.
A cell is placed in a solution that causes it to swell and potentially lyse. Relative to the cell’s cytoplasm, the external solution is best described
as:
A. Hypertonic, with higher solute concentration than the cell
B. Isotonic, with identical solute concentration
C. Hypotonic, with lower solute concentration than the cell, so water enters by osmosis
D. Nonpolar, so no water movement can occur
Correct Answer: C
Rationale: In a hypotonic environment water moves into the cell down its osmotic gradient, increasing volume. Animal cells lacking cell walls may burst under
such conditions.
Q4.
Mitochondria and chloroplasts both contain their own circular DNA and ribosomes. This observation is most consistent with the
endosymbiotic theory, which proposes that these organelles:
A. Descended from free-living prokaryotes that were engulfed by ancestral eukaryotic cells and became symbiotic
B. Arose de novo from invaginations of the plasma membrane alone
C. Were created by the nucleus exporting linear chromosomes
D. Have no evolutionary relationship to any independent organisms
Correct Answer: A
Rationale: Shared features with bacteria—circular DNA, 70S ribosomes, double membranes—support the hypothesis that mitochondria and chloroplasts
originated from endosymbiotic prokaryotes.
Q5.
A scientist labels newly synthesized proteins in a pancreatic cell and tracks them over time. The proteins first appear in the rough ER, then
the Golgi, and finally in secretory vesicles. This pathway demonstrates that:
A. All proteins are synthesized on free cytosolic ribosomes and never enter organelles
B. The nucleus is the sole site of protein synthesis and packaging
C. Secretory and membrane proteins follow the endomembrane trafficking route from ER through Golgi to their destinations
D. Lysosomes are the primary site of protein export from the cell
Correct Answer: C
Rationale: The classic secretory pathway moves proteins from rough ER to Golgi for modification and sorting, then into vesicles for secretion or delivery to
other compartments.
AP Biology Exam | Page 2
AP Biology Exam A+
2026/2027 Official Exam
AP Exam with Questions & Verified Answers 2026/2027
60 Multiple-Choice Questions · Units 1–8 · Application & Analysis Level
A+ QUESTIONS 4 SECTIONS 100%
VERIFIED COVERED RATIONALES
CATEGORIES
■ Chemistry of Life & Cell Structure/Function
■ Cellular Energetics & Cell Communication/Cycle
■ Heredity & Gene Expression/Regulation
■ Natural Selection & Ecology
Examination Specifications
Difficulty: Advanced Placement · Bloom’s: Application / Analysis
Question Format: Multiple Choice (A–D) · Marks: 1 per question
Passing Score: 70% (approx; scaled 1–5, 3+ considered passing) · Total Marks: 60
Content Alignment
This examination is aligned to the publicly available College Board AP Biology Course and Exam Description, covering the chemistry of life, cell
structure and function, cellular energetics, cell communication and the cell cycle, heredity, gene expression and regulation, natural selection, and
ecology.
STUVIAACTUALEXAM
, Section 1: Chemistry of Life & Cell Structure/Function
Q1.
A researcher places a sample of pure phospholipid molecules in water and observes that they spontaneously form bilayers. This behavior is
best explained by the fact that phospholipids are:
A. Amphipathic, with hydrophobic fatty-acid tails that cluster away from water and hydrophilic heads that interact with water
B. Entirely hydrophilic and dissolve completely in water
C. Composed only of saturated fatty acids that solidify at room temperature
D. Unable to form any ordered structure without enzymatic catalysis
Correct Answer: A
Rationale: Phospholipids have hydrophilic phosphate heads and hydrophobic tails. In aqueous environments the tails aggregate inward while heads face
water, producing bilayers—the foundation of cellular membranes.
Q2.
An enzyme-catalyzed reaction proceeds rapidly at pH 7 but slows dramatically at pH 3. The most likely explanation is that the low pH:
A. Increases the activation energy of the reaction beyond any recoverable level
B. Converts the substrate into an entirely different molecule that can never bind
C. Permanently destroys all peptide bonds in the enzyme
D. Alters the ionization of amino-acid side chains, disrupting the enzyme’s active-site shape and substrate binding
Correct Answer: D
Rationale: Extreme pH changes the charge state of critical residues, distorting tertiary structure and the active site so that catalysis is impaired; many such
changes are reversible if conditions are restored.
Q3.
A cell is placed in a solution that causes it to swell and potentially lyse. Relative to the cell’s cytoplasm, the external solution is best described
as:
A. Hypertonic, with higher solute concentration than the cell
B. Isotonic, with identical solute concentration
C. Hypotonic, with lower solute concentration than the cell, so water enters by osmosis
D. Nonpolar, so no water movement can occur
Correct Answer: C
Rationale: In a hypotonic environment water moves into the cell down its osmotic gradient, increasing volume. Animal cells lacking cell walls may burst under
such conditions.
Q4.
Mitochondria and chloroplasts both contain their own circular DNA and ribosomes. This observation is most consistent with the
endosymbiotic theory, which proposes that these organelles:
A. Descended from free-living prokaryotes that were engulfed by ancestral eukaryotic cells and became symbiotic
B. Arose de novo from invaginations of the plasma membrane alone
C. Were created by the nucleus exporting linear chromosomes
D. Have no evolutionary relationship to any independent organisms
Correct Answer: A
Rationale: Shared features with bacteria—circular DNA, 70S ribosomes, double membranes—support the hypothesis that mitochondria and chloroplasts
originated from endosymbiotic prokaryotes.
Q5.
A scientist labels newly synthesized proteins in a pancreatic cell and tracks them over time. The proteins first appear in the rough ER, then
the Golgi, and finally in secretory vesicles. This pathway demonstrates that:
A. All proteins are synthesized on free cytosolic ribosomes and never enter organelles
B. The nucleus is the sole site of protein synthesis and packaging
C. Secretory and membrane proteins follow the endomembrane trafficking route from ER through Golgi to their destinations
D. Lysosomes are the primary site of protein export from the cell
Correct Answer: C
Rationale: The classic secretory pathway moves proteins from rough ER to Golgi for modification and sorting, then into vesicles for secretion or delivery to
other compartments.
AP Biology Exam | Page 2
