Biology Test Biology Cell Structure & Function 3

Question 1

A cell placed in a hypertonic solution will most likely:

Accepted Answer

Shrink due to water loss by osmosis

Answer

In a hypertonic solution, the solute concentration outside is higher than inside the cell, so water moves out by osmosis, causing the cell to shrink (crenation in animal cells).

Question 2

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A dynamic phospholipid bilayer with mobile embedded proteins and cholesterol

Answer

The fluid mosaic model describes the membrane as a flexible phospholipid bilayer in which proteins, cholesterol, and glycolipids can move laterally.

Question 3

What happens to a plant cell in a hypotonic solution?

Accepted Answer

It becomes turgid as water enters but is restrained by the cell wall

Answer

Water enters the plant cell by osmosis, increasing internal pressure (turgor pressure), but the rigid cell wall prevents lysis, making the cell turgid.

Question 4

Which protein channel facilitates the passive transport of water across the cell membrane?

Accepted Answer

Aquaporins

Answer

Aquaporins are specialized channel proteins that allow rapid, selective transport of water molecules across the plasma membrane without energy expenditure.

Question 5

During endocytosis, a cell engulfs a large solid particle by extending pseudopods around it. This specific process is called:

Accepted Answer

Phagocytosis

Answer

Phagocytosis ('cell eating') involves the engulfment of large particles or microorganisms by extending pseudopods that fuse to form a phagosome.

Biology Practice Test

Biology Practice Test

Biology Test Biology Cell Structure & Function 3