$$\text{Osmolarity} = \text{Molarity} \times n$$

Question 1

Which statement best describes the cell theory as presented in the study materials?

Accepted Answer

A cell is the structural and functional unit of life, and continuity of life has a cellular basis.

Question 2

Which of the following is NOT one of the three basic parts of a human cell?

Accepted Answer

Mitochondria

Question 3

A red blood cell is placed in a hypertonic solution. What is the most likely outcome?

Accepted Answer

The cell will shrink due to water leaving the cell, a process called crenation.

Question 4

Which type of membrane protein is firmly inserted into the membrane and often spans the entire bilayer?

Accepted Answer

Integral protein

Question 5

What is the main function of the glycocalyx on the cell surface?

Accepted Answer

To serve as a biological marker for cell-cell recognition

Question 6

Which equation correctly expresses the relationship between osmolarity and molarity for a solute that dissociates into $$n$$ particles?

Accepted Answer

$$	ext{Osmolarity} = 	ext{Molarity} 	imes n$$

Question 7

Which of the following molecules is most likely to diffuse directly through the phospholipid bilayer by simple diffusion?

Accepted Answer

Oxygen ($$	ext{O}_2)$$

Question 8

A solution with a lower osmolarity than the cytoplasm of a cell is described as:

Accepted Answer

Hypotonic

Question 9

Which type of cell junction is most important in preventing the leakage of extracellular fluid between adjacent epithelial cells in the intestine?

Accepted Answer

Tight junction

Question 10

Which of the following best describes facilitated diffusion?

Accepted Answer

Passive movement of molecules down their concentration gradient with the help of carrier or channel proteins

Question 11

If a cell is placed in a solution and water moves into the cell, causing it to swell, what type of solution is the cell in?

Accepted Answer

Hypotonic

Question 12

Which of the following is a function of peripheral membrane proteins?

Accepted Answer

Serving as enzymes and providing structural support

Question 13

Which pressure is responsible for the tendency of water to be 'pulled' into a cell with higher solute concentration?

Accepted Answer

Osmotic pressure

Question 14

Which of the following best explains why glucose requires facilitated diffusion to cross the plasma membrane?

Accepted Answer

Glucose is a large polar molecule and cannot pass through the hydrophobic core of the membrane.

Question 15

Which of the following is TRUE regarding desmosomes?

Accepted Answer

They provide anchoring strength and allow 'give' between cells to reduce tearing under tension.

Question 16

Which type of membrane transport requires no energy input and moves substances down their concentration gradient?

Accepted Answer

Passive transport

Question 17

Which of the following is a correct statement about aquaporins?

Accepted Answer

They are water channels that facilitate osmosis.

Question 18

A solution contains 1 M $$	ext{CaCl}_2. $$What is its osmolarity?

Accepted Answer

$$3~	ext{osmol/L}$$

Question 19

Which of the following best describes the role of membrane proteins in signal transduction?

Accepted Answer

They bind specific chemical messengers and initiate a chain of chemical reactions inside the cell.

Question 20

Which of the following factors does NOT increase the rate of diffusion across the plasma membrane?

Accepted Answer

Lowering the temperature

Cells: The Living Units – Structure, Diversity, and Organization

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