Question 1

Which of the following best describes the function of the plasma (cell) membrane according to the fluid mosaic model?

Accepted Answer

It is a flexible structure composed mainly of phospholipids and proteins, allowing selective permeability and communication.

Question 2

A patient is diagnosed with a genetic disorder that affects the production of cholesterol in cell membranes. Which of the following consequences is most likely to occur in their cells?

Accepted Answer

Decreased membrane stability and increased susceptibility to temperature changes.

Question 3

Which of the following best explains why the plasma membrane is described as a 'selective barrier'?

Accepted Answer

It determines which substances can enter or exit the cell based on their size, charge, and solubility.

Question 4

A researcher adds a dye that binds specifically to hydrophilic regions of the plasma membrane. Where would the dye most likely be found?

Accepted Answer

On the phosphate heads facing the extracellular and intracellular fluids.

Question 5

Which of the following is a function of the glycocalyx on the plasma membrane?

Accepted Answer

Serving as a marker for cell-to-cell recognition.

Question 6

If a cell is placed in a solution where the concentration of solutes is higher outside the cell than inside, what will most likely happen due to osmosis?

Accepted Answer

Water will move out of the cell, causing it to shrink.

Question 7

Which of the following best describes the arrangement of phospholipids in the plasma membrane?

Accepted Answer

Phospholipids form a bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward.

Question 8

A mutation causes a cell to lack tight junctions. Which of the following is a likely consequence?

Accepted Answer

Substances may leak between adjacent cells, compromising tissue barriers.

Question 9

Which of the following statements about membrane proteins is correct?

Accepted Answer

Membrane proteins can function as channels, receptors, or enzymes.

Question 10

A cell is observed to have a large number of desmosomes. Which tissue type is this cell most likely a part of?

Accepted Answer

Epithelial tissue, where strong adhesion between cells is required.

Question 11

Which of the following best explains why the plasma membrane is described as a 'fluid mosaic'?

Accepted Answer

It consists of a dynamic arrangement of lipids and proteins that can move laterally within the layer.

Question 12

Which of the following would most likely increase the fluidity of the plasma membrane at low temperatures?

Accepted Answer

Increasing the cholesterol content within the membrane.

Question 13

A scientist is studying a cell that is unable to recognize neighboring cells. Which component of the plasma membrane is most likely defective?

Accepted Answer

Glycocalyx

Question 14

Which of the following is NOT a function of the plasma membrane?

Accepted Answer

Synthesizing proteins for cellular use.

Question 15

If a cell's plasma membrane lost all of its cholesterol, which of the following would most likely occur?

Accepted Answer

The membrane would become too fluid and less stable.

Question 16

Which of the following best describes the role of proteins in the plasma membrane?

Accepted Answer

They act as channels, receptors, and enzymes, facilitating transport and communication.

Question 17

A cell is exposed to a toxin that destroys its glycocalyx. Which of the following processes would be most directly affected?

Accepted Answer

Cell-to-cell recognition and immune response.

Question 18

Which of the following statements about the hydrophobic and hydrophilic regions of the plasma membrane is correct?

Accepted Answer

Hydrophilic heads face both the extracellular and intracellular fluids, while hydrophobic tails face each other inside the bilayer.

Question 19

Which of the following best explains why the plasma membrane is essential for maintaining homeostasis in the cell?

Accepted Answer

It controls the movement of substances, allowing the cell to regulate its internal environment.

BIO 211 Anatomy & Physiology: Chapter 03 - Cells

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