$$\text{Surface Area} = 4\pi r^2$, $$\text{Volume} = \frac{4}{3}\pi $$r^3$$

Question 1

Which of the following best explains why cells are typically small in size?

Accepted Answer

Smaller cells have a higher surface area-to-volume ratio, allowing efficient exchange of materials with their environment.

Question 2

A scientist wants to study the internal structure of mitochondria in detail. Which type of microscope should they use?

Accepted Answer

Transmission electron microscope (TEM)

Question 3

Which of the following is NOT a feature shared by all cells?

Accepted Answer

Membrane-bound organelles

Question 4

During cell fractionation, which organelle would be found in the pellet after centrifuging at the highest speed?

Accepted Answer

Ribosomes

Question 5

Which of the following statements about prokaryotic cells is correct?

Accepted Answer

Their DNA is located in an unbound region called the nucleoid.

Question 6

A mutation disrupts the function of the nuclear lamina. Which cellular process would be most directly affected?

Accepted Answer

Maintenance of nuclear shape

Question 7

Which organelle is primarily responsible for synthesizing lipids and detoxifying drugs in liver cells?

Accepted Answer

Smooth endoplasmic reticulum (Smooth ER)

Question 8

A protein destined for secretion from a cell will follow which pathway?

Accepted Answer

Rough ER → transport vesicle → Golgi apparatus → plasma membrane

Question 9

Which of the following best supports the endosymbiont theory for the origin of mitochondria and chloroplasts?

Accepted Answer

They contain circular DNA and free ribosomes similar to those in prokaryotes.

Question 10

A plant cell is placed in a hypotonic solution. Which structure prevents the cell from bursting?

Accepted Answer

Cell wall

Question 11

Which cytoskeletal element is most directly involved in separating chromosomes during mitosis?

Accepted Answer

Microtubules

Question 12

Which of the following cell junctions prevents leakage of extracellular fluid between animal cells?

Accepted Answer

Tight junctions

Question 13

A cell is observed to have abundant rough ER and Golgi apparatus. What is the most likely function of this cell?

Accepted Answer

Secretion of large amounts of protein

Question 14

Which equation best represents the relationship between surface area and volume for a spherical cell of radius $$r$$?

Accepted Answer

$$	ext{Surface Area} = 4\pi r^2$, $$	ext{Volume} = \frac{4}{3}\pi $$r^3$$

Question 15

Which of the following is a function of the extracellular matrix (ECM) in animal cells?

Accepted Answer

Regulation of cell behavior and gene activity

Question 16

Which organelle is responsible for digesting macromolecules and recycling cellular components?

Accepted Answer

Lysosome

Question 17

Which cytoskeletal component is most important for muscle contraction?

Accepted Answer

Microfilaments (actin filaments)

Question 18

A mutation causes a defect in dynein motor proteins. Which cellular process would be most directly affected?

Accepted Answer

Movement of cilia and flagella

Question 19

Which structure allows water, small solutes, and sometimes proteins and RNA to pass directly between adjacent plant cells?

Accepted Answer

Plasmodesmata

Question 20

Which of the following best describes the role of the centrosome in animal cells?

Accepted Answer

It organizes microtubules and contains a pair of centrioles.

A Tour of the Cell: Structure, Function, and Organization

Study Guide - Practice Questions