AP Biology Unit 2: Cells

Prokaryotic cells lack membrane-bound organelles but do contain ribosomes for protein synthesis.

The stem asks students to explain a specific mechanism, not just recall a unit term: "Which feature is found in prokaryotic cells". The correct choice is supported by Prokaryotic cells lack membrane-bound organelles but do contain ribosomes for protein synthesis. The tempting alternatives such as membrane-bound nucleus containing linear chromosomes or Chloroplasts surrounded by two membranes fail because they do not produce the same outcome described in the stem.

As a cell grows, volume increases faster than surface area. Smaller cells have relatively more membrane area per unit volume, supporting faster exchange with the environment.

The stem asks students to explain a specific mechanism, not just recall a unit term: "Why do many metabolically active cells remain small instead of growing indefinitely". The correct choice is supported by As a cell grows, volume increases faster than surface area. The tempting alternatives such as Small cells cannot contain DNA or Small cells lack plasma membranes fail because they do not produce the same outcome described in the stem.

Figure 1 must be used to determine which marker is supported by the visual model. Marker D: Cristae expand the inner mitochondrial membrane surface available for electron transport proteins and ATP synthase. Cristae increase inner membrane surface area, allowing more electron transport chain and ATP synthase complexes to participate in oxidative phosphorylation.

The evidence in the prompt matters before the topic label: "A diagram of a mitochondrion shows many folds in the inner membrane. Which statement best connects this structure...". The supported answer is "folds increase surface area for proteins involved in ATP production" because Cristae increase inner membrane surface area, allowing more electron transport chain and ATP synthase complexes to participate in oxidative phosphorylation. Distractors such as folds prevent protons from contributing to chemiosmosis or folds decrease membrane surface area and reduce ATP production either ignore the stated pattern or name a related concept without matching the evidence.