Question 1

Which of the following best describes the main difference between autotrophs and heterotrophs in terms of energy acquisition?

Accepted Answer

Autotrophs produce their own energy from inorganic sources, while heterotrophs obtain energy by consuming organic molecules.

Question 2

During cellular respiration, which molecule acts as the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 3

Which process in cellular respiration directly produces the most ATP?

Accepted Answer

Electron transport chain and oxidative phosphorylation

Question 4

In photosynthesis, what is the primary role of chlorophyll?

Accepted Answer

To absorb light energy and transfer it to reaction centers

Question 5

Which equation correctly represents the overall process of cellular respiration?

Accepted Answer

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

Question 6

Which of the following statements about the Calvin cycle is correct?

Accepted Answer

It uses ATP and NADPH to fix carbon dioxide into organic molecules.

Question 7

A plant is exposed to light but deprived of carbon dioxide. Which process will be most directly affected?

Accepted Answer

Calvin cycle (carbon fixation)

Question 8

Which macromolecule is primarily responsible for catalyzing biochemical reactions in cells?

Accepted Answer

Proteins (enzymes)

Question 9

Why do plants need both photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis produces glucose and oxygen, while cellular respiration breaks down glucose to release usable energy (ATP).

Question 10

Which of the following best explains why C4 plants are more efficient than C3 plants in hot, dry environments?

Accepted Answer

C4 plants spatially separate carbon fixation from the Calvin cycle, reducing photorespiration.

Question 11

Which of the following is a product of the light-dependent reactions of photosynthesis?

Accepted Answer

ATP

Question 12

A mutation causes a plant to lack functional ATP synthase in its chloroplasts. What is the most likely consequence?

Accepted Answer

The plant will be unable to produce ATP during photosynthesis, impairing the Calvin cycle.

Question 13

Which of the following statements about glycolysis is true?

Accepted Answer

Glycolysis occurs in the cytoplasm and does not require oxygen.

Question 14

Which equation represents the overall process of photosynthesis?

Accepted Answer

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

Question 15

Which of the following best describes the role of NADH and FADH$$_2 in $$cellular respiration?

Accepted Answer

They carry electrons to the electron transport chain for ATP production.

Question 16

A scientist measures the rate of oxygen production in a plant under different light intensities. Which process is being studied?

Accepted Answer

Photosynthesis

Question 17

Which of the following is NOT a function of carbohydrates in living organisms?

Accepted Answer

Catalyzing biochemical reactions

Question 18

In which organelle does the citric acid cycle (Krebs cycle) occur?

Accepted Answer

Mitochondrion

Question 19

Which of the following best explains why photorespiration is considered wasteful for plants?

Accepted Answer

It consumes oxygen and releases carbon dioxide without producing ATP or sugars.

Question 20

Which statement best describes the relationship between photosynthesis and cellular respiration in the global carbon cycle?

Accepted Answer

Photosynthesis absorbs carbon dioxide and releases oxygen, while cellular respiration absorbs oxygen and releases carbon dioxide.

Cellular Respiration, Photosynthesis, and Carbohydrate Metabolism Study Guide

Study Guide - Practice Questions