Q: Which of the following best describes the overall chemical equation for photosynthesis in plants?

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

Question 1

Which of the following best describes the overall chemical equation for photosynthesis in plants?

Accepted Answer

$$6CO_2 + 6H_2O + 	ext{light energy} ightarrow C_6H_{12}O_6$ + 6O_2$$

Question 2

Which structure within the chloroplast is the primary site of the light reactions of photosynthesis?

Accepted Answer

Thylakoid membrane

Question 3

What is the main role of chlorophyll a in photosynthesis?

Accepted Answer

To capture light energy and transfer excited electrons to the primary electron acceptor

Question 4

During the light reactions, what is the fate of the electrons released from the splitting of water?

Accepted Answer

They are transferred to NADP$$^+$$, forming NADPH

Question 5

Which of the following statements about autotrophs and heterotrophs is correct?

Accepted Answer

Autotrophs are the producers of the biosphere

Question 6

Which process in photosynthesis is responsible for the production of ATP?

Accepted Answer

Photophosphorylation during the light reactions

Question 7

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

Accepted Answer

The rate will decrease because chlorophyll reflects green light rather than absorbing it

Question 8

Which of the following best explains why photosynthesis is considered an endergonic process?

Accepted Answer

It requires an input of energy from sunlight to drive the reaction

Question 9

In the Calvin cycle, what is the primary function of NADPH?

Accepted Answer

To provide electrons for the reduction of carbon compounds

Question 10

Which of the following is a correct description of the flow of electrons during the light reactions of photosynthesis?

Accepted Answer

Water $$\rightarrow$$ Photosystem II $$\rightarrow$$ Electron Transport Chain $$\rightarrow$$ Photosystem I $$\rightarrow$$ NADP$$^+$$

Question 11

A mutation prevents the regeneration of the CO$$_2$$ acceptor in the Calvin cycle. What is the most immediate consequence for the plant?

Accepted Answer

The Calvin cycle will halt because it cannot fix more CO$$_2$$

Question 12

Which of the following best describes the role of the primary electron acceptor in the reaction-center complex of a photosystem?

Accepted Answer

It captures excited electrons from chlorophyll a and initiates the electron transport chain

Question 13

Why is oxygen produced as a by-product during the light reactions of photosynthesis?

Accepted Answer

Because water is split to provide electrons to Photosystem II

Question 14

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

Accepted Answer

It uses ATP and NADPH to convert CO$$_2$$ into sugar

Question 15

A scientist exposes a plant to light with a wavelength of 700 nm. Which photosystem is most likely to be activated, and what is the significance?

Accepted Answer

Photosystem I; it is most efficient at absorbing 700 nm light

Question 16

Which of the following best explains the importance of the proton gradient across the thylakoid membrane?

Accepted Answer

It drives the synthesis of ATP via chemiosmosis

Question 17

If a plant's thylakoid membranes were punctured so that the interior of the thylakoid was no longer separated from the stroma, which process would be most directly affected?

Accepted Answer

Synthesis of ATP

Question 18

Which of the following is a real-world application of understanding photosynthesis in agriculture?

Accepted Answer

Optimizing light conditions in greenhouses to maximize crop yield

Question 19

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

Accepted Answer

Photosynthesis stores energy in organic molecules, while cellular respiration releases it

Question 20

A plant is genetically modified so that its chlorophyll b is nonfunctional. What is the most likely effect on the plant's photosynthetic efficiency?

Accepted Answer

It will decrease because less light energy will be absorbed and transferred to chlorophyll a

Photosynthesis: The Process That Feeds the Biosphere

Study Guide - Practice Questions

Study Guide - Flashcards