Q: Which equation best represents the direction of water movement during osmosis?

$$ \text{Water moves from an area of low solute concentration to high solute concentration} $$

Question 1

Which of the following best describes the Fluid Mosaic Model of the plasma membrane?

Accepted Answer

A double layer of phospholipids with proteins and cholesterol embedded throughout, allowing lateral movement of components.

Question 2

Doctors administer normal saline or Lactated Ringer's solution intravenously instead of pure water. What is the primary reason for this choice?

Accepted Answer

Saline solutions are isotonic to blood cells, preventing cell lysis due to osmosis.

Question 3

Which of the following factors increases membrane fluidity in animal cell membranes?

Accepted Answer

A high proportion of unsaturated fatty acids in phospholipids.

Question 4

A fish living in cold water is likely to have which adaptation in its cell membrane composition?

Accepted Answer

A high proportion of unsaturated fatty acids to maintain membrane fluidity.

Question 5

Which of the following best explains why the plasma membrane is described as 'selectively permeable'?

Accepted Answer

It allows some molecules to cross while restricting others based on size, polarity, and charge.

Question 6

Which type of molecule can diffuse most easily through the phospholipid bilayer of the plasma membrane?

Accepted Answer

Small, nonpolar molecules

Question 7

Which of the following is an example of passive transport across the cell membrane?

Accepted Answer

Diffusion of oxygen from high to low concentration

Question 8

A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

It will swell and may burst as water enters the cell.

Question 9

Which of the following statements about membrane proteins is correct?

Accepted Answer

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

Question 10

Which of the following best describes the role of carbohydrates on the outer surface of the plasma membrane?

Accepted Answer

They serve as recognition sites for cell-cell interactions and immune responses.

Question 11

Which of the following molecules requires a transport protein to cross the plasma membrane?

Accepted Answer

Glucose

Question 12

Which equation best represents the direction of water movement during osmosis?

Accepted Answer

$$ 	ext{Water moves from an area of low solute concentration to high solute concentration} $$

Question 13

A cell is placed in a solution and water moves out of the cell. What can you conclude about the solution?

Accepted Answer

The solution is hypertonic to the cell.

Question 14

Which of the following best explains why glucose cannot diffuse freely through the plasma membrane?

Accepted Answer

Glucose is large and polar, requiring a transport protein.

Question 15

Which of the following is true about active transport?

Accepted Answer

It requires energy, often in the form of ATP, to move substances against their concentration gradient.

Question 16

Which of the following scenarios best illustrates the concept of facilitated diffusion?

Accepted Answer

Glucose entering a cell through a specific carrier protein down its concentration gradient.

Question 17

Which of the following is a function of glycoproteins in the plasma membrane?

Accepted Answer

Facilitating cell-cell recognition and communication.

Question 18

If a cell's membrane proteins responsible for glucose transport become saturated, what will happen to the rate of glucose uptake as external glucose concentration increases further?

Accepted Answer

The rate of glucose uptake will plateau at a maximum value.

Question 19

Which of the following best describes the movement of sodium ions (Na$$ ^+ ) $$across the plasma membrane during nerve signaling?

Accepted Answer

Na$$ ^+ $$ ions move through specific channel proteins in response to a signal.

Question 20

Which of the following best explains how immune cells distinguish 'self' from 'non-self'?

Accepted Answer

By recognizing unique carbohydrate patterns (glycocalyx) on the surface of cells.

Cell Membrane Structure, Transport, and Signaling – Study Notes for General Biology

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