$$D = k \times A \times (C_1$ - C_2$) / d$$

Question 1

Which of the following best describes the process of diffusion across a cell membrane?

Accepted Answer

Movement of molecules from an area of high concentration to low concentration without energy input.

Question 2

A concentration gradient is essential for which cellular process?

Accepted Answer

Any process involving movement of substances from high to low concentration, such as diffusion.

Question 3

Which equation correctly represents Fick's Law for the rate of diffusion?

Accepted Answer

$$D = k 	imes A 	imes (C_1$ - C_2$) / d$$

Question 4

Which of the following factors would increase the rate of diffusion across a cell membrane?

Accepted Answer

Increasing the concentration gradient across the membrane.

Question 5

An electrical gradient across a membrane affects the movement of which type of molecules most directly?

Accepted Answer

Ions.

Question 6

Which statement best describes a cell membrane that is selectively permeable?

Accepted Answer

It allows some substances to pass while restricting others.

Question 7

Which of the following is an example of active transport in cells?

Accepted Answer

Sodium-potassium pump ($$Na^+/K^+$$ ATPase).

Question 8

The $$Na^+/K^+$$ ATPase pump moves sodium and potassium ions against their concentration gradients. What is the net result of one cycle of this pump?

Accepted Answer

3 $$Na^+$$ ions out, 2 $$K^+$$ ions in, and 1 ATP consumed.

Question 9

Which of the following best explains the difference between primary and secondary active transport?

Accepted Answer

Primary active transport uses ATP directly, while secondary active transport uses the energy stored in ion gradients.

Question 10

Which gradient is responsible for the movement of solvent in osmosis?

Accepted Answer

Concentration gradient of water (solvent).

Question 11

A red blood cell placed in a hypertonic solution will:

Accepted Answer

Shrink due to water leaving the cell (crenation).

Question 12

Which of the following best describes the amphipathic nature of phospholipids in the cell membrane?

Accepted Answer

They have both hydrophilic and hydrophobic regions.

Question 13

Which of the following is NOT a function of cholesterol in the cell membrane?

Accepted Answer

Serving as a receptor for hormones.

Question 14

Which of the following structures is found only in eukaryotic cells and is responsible for ATP production?

Accepted Answer

Mitochondrion.

Question 15

Which parent do humans inherit their mitochondria from?

Accepted Answer

Mother only.

Question 16

Which of the following best describes the function of microvilli in epithelial cells?

Accepted Answer

Increase surface area for absorption.

Question 17

Which process involves the engulfing of large particles by the cell membrane to form a vesicle?

Accepted Answer

Phagocytosis.

Question 18

Which of the following is a correct sequence for the steps of phagocytosis?

Accepted Answer

Attachment, ingestion, digestion, exocytosis.

Question 19

Which of the following best explains why mitochondria are called the 'powerhouses' of the cell?

Accepted Answer

They produce ATP through cellular respiration.

Cellular Form and Function: Movement of Molecules, Membrane Structure, and Organelles

Study Guide - Practice Questions