Question 1

Which of the following best describes the role of chlorophyll in photosynthesis?

Accepted Answer

Chlorophyll is a pigment that absorbs solar energy and initiates the conversion of light energy to chemical energy.

Question 2

Which equation correctly represents the overall process of photosynthesis?

Accepted Answer

$6 \mathrm{CO}_2 + 6 \mathrm{H}_2O \rightarrow C_6H_{12}O_6 + 6 \mathrm{O}_2$

Question 3

In the light reactions of photosynthesis, what is the primary function of the electron transport chain (ETC)?

Accepted Answer

To pump protons into the thylakoid lumen, creating a gradient used to synthesize ATP.

Question 4

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

Accepted Answer

It incorporates carbon dioxide into organic molecules in the stroma.

Question 5

Photosynthetic organisms are classified as:

Accepted Answer

Photoautotrophs, because they use light energy to produce food.

Question 6

Which of the following best explains why plants produce oxygen during photosynthesis?

Accepted Answer

Oxygen is released as a waste product when water is split during the light reactions.

Question 7

Which part of the chloroplast is the site of the light-dependent reactions?

Accepted Answer

Thylakoid membrane

Question 8

What is the main purpose of the Calvin cycle in photosynthesis?

Accepted Answer

To convert carbon dioxide into glucose using ATP and NADPH.

Question 9

Which of the following wavelengths of light is most efficiently absorbed by chlorophyll a?

Accepted Answer

Red and blue light (around 430 nm and 662 nm)

Question 10

Why does fluorescence occur in chlorophyll molecules?

Accepted Answer

Because there is no available electron acceptor for the excited electron.

Question 11

Which of the following is a correct comparison between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis is a redox process that reduces carbon dioxide, while cellular respiration oxidizes glucose.

Question 12

A scientist exposes a plant to only green light. What is the most likely outcome for the rate of photosynthesis?

Accepted Answer

It will decrease because green light is mostly reflected, not absorbed.

Question 13

Which of the following best describes the function of NADPH in photosynthesis?

Accepted Answer

NADPH acts as an electron donor in the Calvin cycle, helping to reduce carbon dioxide.

Question 14

Which of the following is a direct product of the light reactions of photosynthesis?

Accepted Answer

ATP and NADPH

Question 15

What is the role of water in the light-dependent reactions?

Accepted Answer

Water donates electrons to replace those lost by chlorophyll, producing oxygen as a byproduct.

Question 16

Which structure within the chloroplast contains the photosystems and is the site of the light reactions?

Accepted Answer

Thylakoid membrane

Question 17

If a plant is placed in an environment with no carbon dioxide, which process will be directly affected?

Accepted Answer

The Calvin cycle will be unable to synthesize glucose.

Question 18

Which of the following best explains why ATP synthase is able to produce ATP during photosynthesis?

Accepted Answer

ATP synthase uses the energy from a proton gradient established across the thylakoid membrane.

Question 19

Which of the following is NOT a product of the light-dependent reactions of photosynthesis?

Accepted Answer

Glucose

Photosynthesis: Using Light to Make Food

Study Guide - Practice Questions