AP Biology: AP Biology: Cell Structure Practice Questions
Test yourself on AP Biology: Cell Structure with 12 original AP Exams practice questions. Pick an answer to see instant feedback and a full explanation.
Free original practice questions for study purposes. Open Exam Prep is an independent study resource and is not affiliated with, endorsed by, or sponsored by the makers of AP Exams.
advertisement
Answer the questions below — you get instant feedback and a full explanation for each.
1. A eukaryotic cell contains many internal membranes. Which organelle is most directly responsible for modifying, sorting, and packaging proteins for secretion?
Explanation. The Golgi apparatus receives proteins from the rough endoplasmic reticulum, modifies them, sorts them, and packages them into vesicles. Ribosomes build polypeptides, smooth ER is more involved with lipids and detoxification, and mitochondria make ATP.
2. Which feature is found in both prokaryotic and eukaryotic cells?
Explanation. Both prokaryotic and eukaryotic cells use ribosomes to translate mRNA into proteins. Prokaryotes lack a membrane-bound nucleus and membrane-bound organelles such as mitochondria and Golgi apparatus.
3. A cell has many infoldings in its inner mitochondrial membrane. What is the main advantage of these cristae?
Explanation. Cristae increase the surface area of the inner mitochondrial membrane, where the electron transport chain and ATP synthase are located. More membrane surface allows more ATP-producing machinery to operate.
4. A researcher treats animal cells with a drug that disrupts microtubules. Which process would most directly be impaired?
Explanation. Microtubules form the mitotic spindle, which separates chromosomes during cell division. Translation and peptide-bond formation depend mainly on ribosomes, while oxygen diffusion through the membrane does not require microtubules.
5. Which observation best supports the endosymbiotic origin of mitochondria and chloroplasts?
Explanation. Mitochondria and chloroplasts have their own circular DNA, bacterial-like ribosomes, and can divide by a process similar to binary fission. These traits support the idea that they originated from free-living prokaryotes.
6. A white blood cell engulfs bacteria and then digests them inside the cell. Which organelle contains hydrolytic enzymes that carry out this digestion?
Explanation. Lysosomes contain hydrolytic enzymes that break down macromolecules, pathogens, and worn-out cell components. The nucleolus makes ribosomal RNA, the rough ER helps make proteins, and central vacuoles are most prominent in plant cells.
7. Which statement best explains why plant cells can remain firm when placed in a hypotonic environment?
Explanation. In a hypotonic environment, water enters a plant cell and the central vacuole expands. The rigid cell wall resists further expansion, creating turgor pressure that helps the cell remain firm instead of bursting.
8. A pancreatic cell secretes large amounts of digestive enzymes. Which cellular structure would you expect to be especially abundant?
Explanation. Cells that secrete proteins usually have extensive rough endoplasmic reticulum because ribosomes on the rough ER synthesize proteins destined for secretion or membranes. Digestive enzymes are proteins.
9. Which structure is directly responsible for regulating what enters and leaves the cell?
Explanation. The plasma membrane is a selectively permeable phospholipid bilayer with embedded proteins. It controls transport into and out of the cell through channels, carriers, pumps, and vesicle-based transport.
10. A cell has a high concentration of peroxisomes. Which activity is most likely common in that cell?
Explanation. Peroxisomes contain enzymes that break down fatty acids and detoxify hydrogen peroxide by converting it to water and oxygen. Chromosome storage is nuclear, ribosomal subunits form in the nucleolus, and cellulose production is associated with plant cell walls.
11. Which comparison between prokaryotic and eukaryotic cells is accurate?
Explanation. Prokaryotes generally have DNA concentrated in a nucleoid region without a nuclear membrane. Eukaryotes enclose most DNA inside a nucleus. Both cell types have plasma membranes, cytoplasm, and ribosomes.
12. A mutation prevents vesicles from fusing with the plasma membrane. Which cellular process would be most directly reduced?
Explanation. Exocytosis requires transport vesicles to fuse with the plasma membrane and release contents outside the cell. DNA replication, glycolysis, and osmosis through aquaporins do not require vesicle fusion with the membrane.
📘 Want a full structured course and official-style practice tests? Browse top-rated AP Exams prep books and courses. Some links are affiliate links; we may earn a commission at no cost to you.
advertisement
FAQ
What cell structures should I know first for AP Biology?
Start with nucleus, ribosomes, rough and smooth ER, Golgi apparatus, mitochondria, chloroplasts, lysosomes, peroxisomes, vacuoles, plasma membrane, cell wall, and the cytoskeleton. For each one, connect structure to function.
How does AP Biology test cell structure?
Questions often ask you to predict what happens when an organelle or cytoskeletal component is disrupted. Practice linking a cell type's job, such as protein secretion or ATP production, to the structures it needs most.
What is a common mistake on cell structure questions?
A common mistake is memorizing organelle names without understanding transport flow. For secreted proteins, remember the path: ribosome on rough ER, rough ER, vesicle, Golgi apparatus, vesicle, plasma membrane.