Question 1

Which of the following best explains why mitochondria have highly folded inner membranes?

Accepted Answer

To increase the surface area for ATP synthesis, enhancing the efficiency of aerobic respiration.

Question 2

A cell is observed to have a large central vacuole, chloroplasts, and a cell wall. Which type of cell is this most likely to be?

Accepted Answer

A plant cell

Question 3

Which of the following molecules can most easily diffuse across a plasma membrane without the help of transport proteins?

Accepted Answer

Oxygen (O$$_2)$$

Question 4

A spherical cell has a radius of 2 μm. What is its surface area-to-volume ratio? (Use $$SA = 4\pi r^2$ and V$$ = \frac{4}{3}\pi $$r^3)$$

Accepted Answer

$$\frac{3}{r} = 1.5 ($$correct units)

Question 5

Which of the following best describes the role of the Golgi complex in a eukaryotic cell?

Accepted Answer

It modifies, folds, and packages proteins for trafficking within or out of the cell.

Question 6

A cell is placed in a solution with a lower solute concentration than its cytoplasm. What will most likely happen to the cell?

Accepted Answer

Water will enter the cell, causing it to swell.

Question 7

Which equation correctly represents the calculation of water potential ($$\Psi) in $$plant cells?

Accepted Answer

$$\Psi = \Psi_p + \Psi_s$$

Question 8

Which of the following is a function of lysosomes in animal cells?

Accepted Answer

Digesting macromolecules and recycling cellular components

Question 9

Which process requires energy input from ATP to move substances across the plasma membrane?

Accepted Answer

Active transport

Question 10

A scientist observes a cell with no internal membrane-bound organelles but with specialized internal regions. This cell is most likely:

Accepted Answer

A prokaryotic cell

Question 11

Which of the following best explains why smaller cells are more efficient at exchanging materials with their environment?

Accepted Answer

They have a higher surface area-to-volume ratio.

Question 12

Which of the following statements about the fluid mosaic model of the plasma membrane is correct?

Accepted Answer

Phospholipids and proteins can move laterally within the layer, allowing flexibility.

Question 13

Which of the following best describes the movement of water across a selectively permeable membrane?

Accepted Answer

Osmosis, from regions of high water potential to low water potential

Question 14

Which of the following is a real-world example of active transport in human physiology?

Accepted Answer

The sodium-potassium pump moving Na$$^+$$ out of and K$$^+$$ into nerve cells

Question 15

Which equation is used to calculate the solute potential ($$\Psi_s) of a $$solution?

Accepted Answer

$$\Psi_s = -iCRT$$

Question 16

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

Accepted Answer

They contain their own DNA and double membranes.

Question 17

A cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

It will lose water and shrink.

Question 18

Which of the following is a function of the cell wall in plant cells?

Accepted Answer

Providing structural support and protection from osmotic lysis

Question 19

Which process describes the movement of large molecules into a cell by the formation of vesicles from the plasma membrane?

Accepted Answer

Endocytosis

Question 20

Which of the following best explains why internal membranes are important in eukaryotic cells?

Accepted Answer

They compartmentalize metabolic processes, increasing efficiency and minimizing competing interactions.

Cell Structure, Membrane Function, and Transport Mechanisms

Study Guide - Practice Questions