AP Biology Unit 2 Practice Test: Cells
Practise AP Biology Unit 2 with tests on prokaryotic and eukaryotic cells, membrane structure, osmosis, and active transport. AP-style MCQ and FRQ questions.
What Unit 2 Covers in AP Biology
Unit 2 moves from molecular chemistry to the cell — life's fundamental structural and functional unit. The AP Biology exam tests your ability to compare cell types, explain organelle roles, and apply membrane transport principles in experimental contexts.
Core Topics in Unit 2
Prokaryotic vs. Eukaryotic Cells
Know the defining features of each cell type: prokaryotes lack membrane-bound organelles and a nucleus; eukaryotes compartmentalise functions across organelles. AP MCQ items commonly test your ability to identify structural features and predict their functional consequences.
Organelle Structure and Function
Each organelle has a specific role tied to its structure. Key organelles include the nucleus, mitochondria, chloroplasts, endoplasmic reticulum (rough and smooth), Golgi apparatus, lysosomes, vacuoles, and ribosomes. AP questions often ask you to trace a protein's path from synthesis to secretion using organelle sequence logic.
Membrane Structure — The Fluid Mosaic Model
The plasma membrane is a dynamic phospholipid bilayer embedded with proteins, cholesterol, and carbohydrates. Understanding fluidity, selective permeability, and the roles of integral and peripheral proteins is essential for both MCQ and FRQ performance.
Passive Transport, Active Transport, and Osmosis
Passive transport (diffusion, facilitated diffusion, osmosis) moves substances down concentration gradients without energy input. Active transport requires ATP to move substances against gradients. Endocytosis and exocytosis move large molecules via vesicle formation.
Cell Size and Surface-Area-to-Volume Ratios
As cell size increases, volume grows faster than surface area — limiting nutrient exchange and waste removal efficiency. AP Biology frequently frames this concept in experimental or quantitative contexts.
AP Science Practice Skills for Unit 2
- Data analysis: Interpreting osmosis experiments (potato core, dialysis tubing) and calculating water potential
- Experimental design: Designing membrane transport investigations with appropriate controls
- Scientific argumentation: Explaining why cells divide using surface-area-to-volume reasoning
How GradePerfect Tests Unit 2
Our AP-style Unit 2 test presents membrane transport diagrams, cell comparison scenarios, and data-driven FRQ prompts that reflect the reasoning demands of the actual AP Biology exam.