PCAT PCAT Cell Biology 2 — Questions and Answers
Question 1: Which type of cell lacks a membrane-bound nucleus and membrane-enclosed organelles?
- Prokaryotic cell (Correct answer)
- Eukaryotic cell
- Animal cell
- Plant cell
Correct answer: Prokaryotic cell
Prokaryotic cells such as bacteria have no nuclear envelope or membrane-bound organelles; their DNA resides in a nucleoid region.
Question 2: What is the primary function of the Golgi apparatus?
- Processing and packaging proteins for secretion or organelle delivery (Correct answer)
- Synthesizing proteins on ribosomes
- Producing ATP through respiration
- Replicating DNA before cell division
Correct answer: Processing and packaging proteins for secretion or organelle delivery
The Golgi receives proteins from the ER, modifies and sorts them, then packages them into vesicles directed to their final destinations.
Question 3: Which transport process requires ATP to move molecules against their concentration gradient?
- Active transport (Correct answer)
- Passive diffusion
- Osmosis
- Facilitated diffusion
Correct answer: Active transport
Active transport uses energy from ATP hydrolysis to move substances 'uphill' against their concentration gradient via carrier proteins.
Question 4: What is the primary function of the cytoskeleton?
- Providing structural support and enabling cell movement (Correct answer)
- Producing cellular energy
- Synthesizing proteins
- Storing genetic information
Correct answer: Providing structural support and enabling cell movement
The cytoskeleton is a network of microfilaments, intermediate filaments, and microtubules that maintains cell shape and facilitates intracellular transport and movement.
Question 5: During which phase of mitosis do chromosomes align along the cell's equatorial plate?
- Metaphase (Correct answer)
- Prophase
- Anaphase
- Telophase
Correct answer: Metaphase
During metaphase, spindle fibers attach to kinetochores and align chromosomes at the metaphase plate, ensuring equal distribution to daughter cells.
Question 6: What term describes the aqueous, gel-like fluid of the cytoplasm that surrounds the organelles?
- Cytosol (Correct answer)
- Nucleoplasm
- Stroma
- Matrix
Correct answer: Cytosol
Cytosol is the soluble fluid component of the cytoplasm containing enzymes, ions, and metabolites that carry out many cellular reactions.
PCAT PCAT Cell Biology 2
Which type of cell lacks a membrane-bound nucleus and membrane-enclosed organelles?