Question 1

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

Accepted Answer

It consists of a phospholipid bilayer with proteins that can move laterally, creating a flexible and varied structure.

Question 2

A scientist observes a cell with a nucleus, mitochondria, and a cell wall made of cellulose. Which type of cell is being observed?

Accepted Answer

Plant cell

Question 3

Which of the following statements about the endosymbiotic theory is supported by evidence from mitochondria and chloroplasts?

Accepted Answer

Both organelles contain their own DNA and ribosomes similar to those of prokaryotes.

Question 4

Which process is responsible for the movement of water across a cell membrane from an area of high water concentration to low water concentration?

Accepted Answer

Osmosis

Question 5

A red blood cell is placed in a hypotonic solution. What is the most likely outcome, and why?

Accepted Answer

The cell will swell and may burst because water enters the cell.

Question 6

Which of the following best describes the role of ATP in cellular work?

Accepted Answer

ATP releases energy when its third phosphate group is removed, powering cellular processes.

Question 7

Which equation correctly represents the overall process of cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$$

Question 8

During strenuous exercise, when oxygen is limited, human muscle cells switch to fermentation. What is a direct consequence of this switch?

Accepted Answer

Accumulation of lactate in muscle tissue

Question 9

Which of the following best explains why enzymes are essential for life?

Accepted Answer

They act as biological catalysts, lowering the activation energy and speeding up reactions.

Question 10

A competitive inhibitor affects an enzyme by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 11

Which of the following is a key adaptive advantage of the folded inner membranes (cristae in mitochondria and thylakoids in chloroplasts)?

Accepted Answer

They increase the surface area for energy-producing reactions.

Question 12

Which of the following best describes the relationship between photosynthesis and cellular respiration?

Accepted Answer

The products of photosynthesis are the reactants for cellular respiration and vice versa.

Question 13

Which of the following statements about the extracellular matrix (ECM) in animal cells is correct?

Accepted Answer

It is a meshwork of glycoproteins that supports and protects the plasma membrane.

Question 14

Which of the following best describes the function of the Golgi apparatus?

Accepted Answer

It modifies, sorts, and packages proteins for export or delivery to other organelles.

Question 15

Which of the following is true regarding the energy yield and location of glycolysis?

Accepted Answer

Glycolysis occurs in the cytoplasm and produces a net gain of 2 ATP per glucose.

Question 16

Which of the following best describes the difference between diffusion and active transport?

Accepted Answer

Diffusion moves substances down their concentration gradient without energy input, while active transport moves substances against their gradient using energy.

Question 17

Which pigment is primarily responsible for absorbing light energy during photosynthesis, and what color does it reflect?

Accepted Answer

Chlorophyll a; reflects green light

Question 18

Which of the following best explains why energy transfers in living systems increase entropy?

Accepted Answer

Some energy is always lost as heat, which is the most disordered form of energy.

Question 19

Which of the following is a correct comparison between the light reactions and the Calvin cycle in photosynthesis?

Accepted Answer

The light reactions produce ATP and NADPH, which are used by the Calvin cycle to fix carbon dioxide into sugars.

Question 20

A patient is exposed to cyanide, a poison that inhibits the electron transport chain. Which cellular process will be directly affected first?

Accepted Answer

ATP production by oxidative phosphorylation

Cell Structure, Function, and Energy: Study Guide for Chapters 4–7

Study Guide - Practice Questions

Study Guide - Flashcards