Question 1

Which of the following statements best explains why nearly all life on Earth can trace its source of energy back to the sun?

Accepted Answer

Solar energy is captured by autotrophs through photosynthesis, forming the basis of most food chains.

Question 2

Which of the following is NOT a product of photosynthesis?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 3

What is the primary function of chlorophyll in the chloroplast?

Accepted Answer

To convert solar energy into chemical energy during photosynthesis

Question 4

Which structure in the leaf allows for the exchange of gases such as $$CO_2$$ and $$O_2$$?

Accepted Answer

Stomata

Question 5

What is the correct overall chemical equation for photosynthesis?

Accepted Answer

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

Question 6

Which of the following best describes the role of autotrophs in ecosystems?

Accepted Answer

They generate their own organic matter from inorganic ingredients.

Question 7

Which pigment is primarily responsible for the green color of leaves and directly participates in the light reactions?

Accepted Answer

Chlorophyll a

Question 8

What is the main difference between the electron transport chain in cellular respiration and photosynthesis?

Accepted Answer

Photosynthesis uses light-excited electrons, while cellular respiration uses electrons from food.

Question 9

During the light reactions of photosynthesis, what is the final electron acceptor?

Accepted Answer

NADP$$^+$$

Question 10

Why is water required as a reactant in photosynthesis?

Accepted Answer

It donates electrons to replace those lost by chlorophyll during the light reactions.

Question 11

Which process in photosynthesis is responsible for the initial incorporation of carbon from the atmosphere into organic compounds?

Accepted Answer

Carbon fixation

Question 12

What is the main product of the Calvin cycle that can be used to synthesize glucose and other organic compounds?

Accepted Answer

Glyceraldehyde 3-phosphate (G3P)

Question 13

Which of the following best describes the function of a photosystem?

Accepted Answer

It is a cluster of pigment molecules that acts as a light-gathering antenna.

Question 14

Which pigment absorbs mainly blue-violet and red light and participates directly in the light reactions?

Accepted Answer

Chlorophyll a

Question 15

What is the role of carotenoids in the chloroplast?

Accepted Answer

They absorb mainly blue-green light and protect the plant from excess light energy.

Question 16

Which of the following is a correct description of the electromagnetic spectrum?

Accepted Answer

It is the range of all possible wavelengths of radiation, including visible light.

Question 17

What happens to an electron in a pigment molecule when it absorbs a photon?

Accepted Answer

It gains energy and becomes excited.

Question 18

Which of the following is a real-world application of photosynthesis in energy production?

Accepted Answer

Burning plant matter to generate electricity

Question 19

During the light reactions, what is the main purpose of the electron transport chain?

Accepted Answer

To pump hydrogen ions across the thylakoid membrane, creating a gradient for ATP synthesis

Question 20

Which of the following best explains why leaves appear green?

Accepted Answer

Chloroplasts poorly absorb green light, which is reflected or transmitted toward the observer.

Chapter 7: Photosynthesis

Study Guide - Practice Questions