Question 1

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

Accepted Answer

A dynamic structure with proteins embedded in or attached to a bilayer of phospholipids.

Question 2

Which factor would most likely increase membrane fluidity in a cell exposed to cold temperatures?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in phospholipids.

Question 3

A red blood cell placed in a hypotonic solution will:

Accepted Answer

Burst as water enters the cell by osmosis.

Question 4

Which equation correctly represents the surface area to volume ratio for a spherical cell?

Accepted Answer

$$\frac{4\pi r^2$}{\frac{4}{3}\pi r^3$}$$

Question 5

Which of the following is a function of membrane proteins?

Accepted Answer

Facilitating the transport of specific substances across the membrane.

Question 6

Which process requires energy input from the cell and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 7

A cell with a large surface area to volume ratio is most likely to:

Accepted Answer

Efficiently exchange materials with its environment.

Question 8

Which organelle is primarily responsible for ATP production in eukaryotic cells?

Accepted Answer

Mitochondrion

Question 9

Which statement best explains why prokaryotic cells are generally smaller than eukaryotic cells?

Accepted Answer

Smaller size increases the surface area to volume ratio, allowing efficient nutrient exchange.

Question 10

Which of the following best describes bulk transport in cells?

Accepted Answer

Transport of large particles or fluids via vesicle formation, such as endocytosis and exocytosis.

Question 11

A mutation causes a cell to produce a defective aquaporin protein. What is the most likely consequence?

Accepted Answer

Impaired water transport across the membrane.

Question 12

Which of the following is true about the endomembrane system in eukaryotic cells?

Accepted Answer

It consists of interconnected membranes such as the ER, Golgi apparatus, and vesicles.

Question 13

Which type of cell junction allows ions and small molecules to pass directly from one animal cell to another?

Accepted Answer

Gap junction

Question 14

Which of the following statements about mitochondria and chloroplasts is correct?

Accepted Answer

Both contain their own DNA and are involved in energy conversion.

Question 15

A cell is observed to have a high rate of endocytosis. Which cellular structure is most directly involved in this process?

Accepted Answer

Plasma membrane

Question 16

Which of the following best explains why cholesterol is important for membrane fluidity?

Accepted Answer

Cholesterol stabilizes the membrane by preventing extremes in fluidity.

Question 17

Which of the following is an example of selective permeability in biological membranes?

Accepted Answer

Only certain ions and molecules are allowed to pass through specific transport proteins.

Question 18

A patient is diagnosed with cystic fibrosis, a disease caused by a defective chloride channel protein. Which membrane property is most directly affected?

Accepted Answer

Selective permeability

Question 19

Which of the following equations represents the calculation for the volume of a sphere, relevant to cell size?

Accepted Answer

$$V = \frac{4}{3}\pi r^3$

Question 20

A scientist observes that a cell is able to move glucose into the cytoplasm even when the concentration of glucose is higher inside the cell than outside. Which process is most likely responsible?

Accepted Answer

Active transport

Cell Structure, Membranes, and Transport: Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard