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

It uses the flow of $$\text{H}^+$$ ions down their concentration gradient to synthesize ATP from ADP and $$\text{P}_i$$

Question 1

Which of the following best describes the overall chemical 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 2

What is the primary function of the stomata in plant leaves?

Accepted Answer

To allow the exchange of gases, specifically the intake of $$	ext{CO}_2$$ and release of $$	ext{O}_2$$

Question 3

Which pigment is primarily responsible for the green color of leaves and is the main pigment involved in the light reactions of photosynthesis?

Accepted Answer

Chlorophyll a

Question 4

Why do leaves change color in the autumn?

Accepted Answer

Chlorophyll breaks down, revealing accessory pigments such as carotenoids and anthocyanins

Question 5

Which of the following best explains why plants appear green to our eyes?

Accepted Answer

Chlorophyll reflects green light and absorbs other wavelengths

Question 6

What is the main purpose of the light reactions in photosynthesis?

Accepted Answer

To convert solar energy into chemical energy in the form of ATP and NADPH

Question 7

During the light reactions, what is the source of electrons that replace those lost by chlorophyll in photosystem II?

Accepted Answer

Water ($$	ext{H}_2	ext{O})$$

Question 8

Which molecule is the final electron acceptor in the light reactions of photosynthesis?

Accepted Answer

NADP$$^+$$

Question 9

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

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 10

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

Accepted Answer

Photosynthesis stores energy in glucose, while cellular respiration releases energy from glucose

Question 11

Which of the following is a correct summary of the energy conversions that occur during photosynthesis?

Accepted Answer

Light energy is converted to chemical energy

Question 12

Which structure within the chloroplast is the site of the light-dependent reactions?

Accepted Answer

Thylakoid membrane

Question 13

What is the role of ATP synthase in the light reactions of photosynthesis?

Accepted Answer

It uses the flow of $$	ext{H}^+$$ ions down their concentration gradient to synthesize ATP from ADP and $$	ext{P}_i$$

Question 14

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

Accepted Answer

It uses ATP and NADPH produced in the light reactions to fix carbon dioxide into organic molecules

Question 15

A plant is exposed to only green light. What is the most likely effect on the rate of photosynthesis?

Accepted Answer

The rate of photosynthesis will decrease because chlorophyll reflects green light

Question 16

Which of the following is a direct by-product of the splitting of water during the light reactions?

Accepted Answer

Oxygen ($$	ext{O}_2)$$

Question 17

Which of the following best explains why accessory pigments are important in photosynthesis?

Accepted Answer

They absorb additional wavelengths of light and transfer energy to chlorophyll a

Question 18

Which of the following is NOT a fate of light when it strikes a leaf?

Accepted Answer

It is converted to sound energy

Question 19

If the stomata of a plant leaf are closed, which process is most directly affected?

Accepted Answer

Gas exchange, specifically the intake of $$	ext{CO}_2$$ and release of $$	ext{O}_2$$

Question 20

Which of the following best describes the role of bundle sheath cells in a leaf?

Accepted Answer

They surround vascular bundles and help regulate the movement of substances between the vascular tissue and mesophyll

Photosynthesis and Cellular Respiration: Structure, Function, and Energy Flow

Study Guide - Practice Questions