Question 1

Which of the following statements best describes the function of the sodium-potassium pump in maintaining cellular homeostasis?

Accepted Answer

It transports 3 sodium ions out of the cell and 2 potassium ions into the cell against their concentration gradients, using ATP.

Question 2

A red blood cell is placed in a solution with a higher solute concentration than its cytoplasm. What will most likely happen to the cell, and what is this solution called?

Accepted Answer

The cell will shrink (crenate); the solution is hypertonic.

Question 3

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

Accepted Answer

It consists of phospholipids and proteins that can move laterally within the layer, along with scattered carbohydrates.

Question 4

During osmosis, water moves across a selectively permeable membrane. Which direction does water move?

Accepted Answer

From a region of lower solute concentration to higher solute concentration.

Question 5

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

Accepted Answer

They form channels that connect the internal and external environments, allowing specific substances to pass through.

Question 6

A cell is placed in a 0.9% NaCl solution, which is isotonic to its cytoplasm. What will happen to the cell?

Accepted Answer

There will be no net movement of water; the cell will remain the same size.

Question 7

Which of the following best describes the process of facilitated diffusion?

Accepted Answer

Movement of molecules from high to low concentration through a carrier protein, without using ATP.

Question 8

Which of the following is true regarding the genetic code and protein synthesis?

Accepted Answer

Each DNA triplet codes for a specific amino acid, and the sequence is transcribed into mRNA codons.

Question 9

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

Accepted Answer

It stabilizes the structure of the membrane, especially as temperature changes.

Question 10

A patient receives an intravenous solution that is hypotonic relative to their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

The cells will gain water, swell, and may burst (hemolysis).

Question 11

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Simple diffusion involves movement directly through the lipid bilayer, while facilitated diffusion requires a protein channel or carrier.

Question 12

Which of the following is a correct base pairing in DNA and RNA?

Accepted Answer

DNA: C-G, A-T; RNA: C-G, A-U

Question 13

Which of the following best describes the process of phagocytosis?

Accepted Answer

The cell engulfs large particles or bacteria by wrapping its membrane around them and forming a vesicle.

Question 14

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

Accepted Answer

Decreasing the distance the molecules must travel.

Question 15

Which of the following is true about the resting membrane potential of a typical cell?

Accepted Answer

It is measured in millivolts (mV) and is usually negative inside the cell relative to the outside.

Question 16

Which of the following best describes the function of glycoproteins in the plasma membrane?

Accepted Answer

They are involved in cell recognition and identification.

Question 17

Which of the following processes requires energy in the form of ATP?

Accepted Answer

Active transport

Question 18

A cell is placed in a solution and water moves into the cell, causing it to swell. Which of the following best describes the solution?

Accepted Answer

The solution is hypotonic to the cell.

Question 19

Which of the following best describes the process of transcription in protein synthesis?

Accepted Answer

The process of copying a gene's DNA sequence into a complementary mRNA sequence.

Question 20

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

Accepted Answer

Synthesizing proteins for the cell.

Chapter 3

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