$$6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2$$

Question 1

Which of the following best describes a photoautotroph?

Accepted Answer

An organism that uses light energy to synthesize organic compounds from inorganic substances.

Question 2

Which of the following is the correct summary equation for photosynthesis?

Accepted Answer

$$6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{light energy} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2$$

Question 3

Which reactant is reduced during photosynthesis?

Accepted Answer

$$	ext{CO}_2$$

Question 4

Which statement correctly compares photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis is endergonic, while cellular respiration is exergonic.

Question 5

A plant is exposed only to green light. What is the most likely outcome for its rate of photosynthesis, and why?

Accepted Answer

The rate will decrease because green light is mostly reflected, not absorbed, by chlorophyll.

Question 6

Which component of the chloroplast is the site of the Calvin cycle?

Accepted Answer

Stroma

Question 7

What is the primary function of the light reactions in photosynthesis?

Accepted Answer

To generate ATP and NADPH for the Calvin cycle

Question 8

Which of the following best describes chemiosmosis in the context of photosynthesis?

Accepted Answer

The diffusion of protons through ATP synthase, driving the phosphorylation of ADP to ATP.

Question 9

Which of the following statements about the relationship between the light reactions and the Calvin cycle is correct?

Accepted Answer

The light reactions provide ATP and NADPH that are used in the Calvin cycle.

Question 10

Which of the following is the primary photosynthetic pigment in plants?

Accepted Answer

Chlorophyll a

Question 11

What is the role of water in the light reactions of photosynthesis?

Accepted Answer

It donates electrons to replace those lost by chlorophyll in Photosystem II.

Question 12

Which process occurs in both photophosphorylation and oxidative phosphorylation?

Accepted Answer

Generation of a proton gradient across a membrane

Question 13

A mutation disables Photosystem II in a plant. Which of the following would be the most immediate effect?

Accepted Answer

The plant would stop producing oxygen during photosynthesis.

Question 14

Which of the following best explains why photoautotrophs are essential to the biosphere?

Accepted Answer

They convert inorganic carbon into organic molecules, providing energy for other organisms.

Question 15

Which of the following is a product of the Calvin cycle?

Accepted Answer

Glucose ($$	ext{C}_6	ext{H}_{12}	ext{O}_6)$$

Question 16

Which enzyme is responsible for carbon fixation in the Calvin cycle?

Accepted Answer

Rubisco

Question 17

If a plant's thylakoid membranes were damaged, which process would be directly affected?

Accepted Answer

The light reactions

Question 18

Which of the following best describes the relationship between wavelength and energy in the electromagnetic spectrum?

Accepted Answer

Shorter wavelengths have higher energy.

Question 19

Which of the following is a key difference between photophosphorylation in photosynthesis and oxidative phosphorylation in cellular respiration?

Accepted Answer

Photophosphorylation uses light energy, while oxidative phosphorylation uses chemical energy from food molecules.

Question 20

A scientist exposes a plant to a chemical that blocks ATP synthase in the chloroplast. What is the most immediate effect on photosynthesis?

Accepted Answer

The plant will be unable to produce ATP needed for the Calvin cycle.

Chapter 7: Photosynthesis – Study Guide and Key Concepts

Study Guide - Practice Questions