Question 1

Which of the following best describes the overall purpose of photosynthesis in plants?

Accepted Answer

To transform light energy into chemical energy stored in organic molecules

Question 2

Where in the chloroplast do the light-dependent reactions of photosynthesis occur?

Accepted Answer

In the thylakoid membranes

Question 3

Which pigment is primarily responsible for capturing light energy in photosynthesis?

Accepted Answer

Chlorophyll

Question 4

What is the correct balanced equation for the light-dependent reaction of photosynthesis?

Accepted Answer

$$H_2O + NADP^+ + ADP \Rightarrow O_2$ + NADPH + ATP$$

Question 5

During the light-dependent reactions, what is the role of NADP$$^+$$?

Accepted Answer

It is reduced to NADPH, storing high-energy electrons

Question 6

Which structure within the chloroplast is directly involved in the synthesis of ATP during photosynthesis?

Accepted Answer

Thylakoid membrane

Question 7

What is the main function of the Calvin-Benson cycle in photosynthesis?

Accepted Answer

To fix atmospheric CO$$_2$$ into organic molecules using ATP and NADPH

Question 8

Which of the following is NOT a phase of the Calvin-Benson cycle?

Accepted Answer

Photolysis of water

Question 9

If a plant is exposed only to light with a wavelength of 800 nm, which of the following is most likely to occur?

Accepted Answer

Photosynthesis will decrease because 800 nm is outside the visible light range

Question 10

Which process is responsible for the production of ATP during the light-dependent reactions?

Accepted Answer

Photophosphorylation via chemiosmosis

Question 11

What is the role of water ($$H_2O) in $$the light-dependent reactions?

Accepted Answer

It donates electrons to replace those lost by photosystem II, producing $$O_2 as a $$byproduct

Question 12

Which of the following best explains why plants appear green?

Accepted Answer

Chlorophyll reflects green light and absorbs red and blue light

Question 13

A mutation disables the electron transport system in the thylakoid membrane. Which immediate effect would this have on photosynthesis?

Accepted Answer

ATP and NADPH production would decrease

Question 14

Which of the following is the correct summary equation for the Calvin-Benson cycle?

Accepted Answer

$$6CO_2 + 18 ATP + 12 NADPH \Rightarrow 1 C_6H_{12}O_6$ + 18 ADP + 12 NADP^+$$

Question 15

Which of the following statements about the stroma of the chloroplast is TRUE?

Accepted Answer

It contains the enzymes for the Calvin-Benson cycle

Question 16

Which of the following is a direct product of the light-dependent reactions and is used in the Calvin-Benson cycle?

Accepted Answer

NADPH

Question 17

A plant is genetically modified to lack accessory pigments. What is the most likely consequence?

Accepted Answer

It will absorb a narrower range of light wavelengths, reducing photosynthetic efficiency

Question 18

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

Accepted Answer

They convert light energy into chemical energy by exciting electrons

Question 19

If the proton gradient across the thylakoid membrane is disrupted, which process will be directly affected?

Accepted Answer

ATP synthesis by chemiosmosis

Question 20

Which of the following is TRUE regarding the fate of ADP and NADP$$^+$$ after the Calvin-Benson cycle?

Accepted Answer

They return to the light-dependent reactions to be recharged

Photosynthesis: Capturing Solar Energy in Plants

Study Guide - Practice Questions