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

During the light reactions of photosynthesis, which molecule acts as the final electron acceptor?

Accepted Answer

$$NADP^+$$

Question 3

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

Accepted Answer

It uses ATP and NADPH to convert $$CO_2$$ into G3P.

Question 4

A plant is exposed to light, but its thylakoid membranes are damaged so that they are no longer intact. Which process will be most directly affected?

Accepted Answer

Generation of a proton gradient for ATP synthesis

Question 5

Which pigment is primarily responsible for the green color of leaves and is essential for the light reactions?

Accepted Answer

Chlorophyll a

Question 6

What is the main function of the light-harvesting complexes in a photosystem?

Accepted Answer

To capture photons and transfer energy to the reaction-center chlorophyll

Question 7

Which of the following best explains why plants close their stomata on hot, dry days?

Accepted Answer

To conserve water, even though it limits $$CO_2$$ uptake

Question 8

Photorespiration occurs when rubisco incorporates $$O_2$$ instead of $$CO_2$$ into the Calvin cycle. What is a consequence of this process?

Accepted Answer

It consumes ATP and releases $$CO_2$$ without producing sugar

Question 9

Which of the following is a key adaptation in C4 plants that minimizes photorespiration?

Accepted Answer

Spatial separation of carbon fixation and the Calvin cycle

Question 10

A researcher exposes isolated chlorophyll molecules to light in a test tube. The solution glows red when illuminated. What is the best explanation for this observation?

Accepted Answer

The excited electrons return to the ground state, releasing energy as fluorescence

Question 11

Which of the following statements about chemiosmosis in chloroplasts is correct?

Accepted Answer

Protons flow from the thylakoid space into the stroma through ATP synthase

Question 12

Which of the following is a direct product of the Calvin cycle that can be used to synthesize glucose and other organic molecules?

Accepted Answer

Glyceraldehyde 3-phosphate (G3P)

Question 13

Which of the following best describes the role of water in the light reactions of photosynthesis?

Accepted Answer

It is split to provide electrons to photosystem II and releases $$O_2$$

Question 14

Which of the following is true about CAM plants?

Accepted Answer

They fix $$CO_2 at $$night and release it for the Calvin cycle during the day

Question 15

A plant is placed in an environment with only green light. What is the most likely effect on its rate of photosynthesis?

Accepted Answer

It will decrease, because chlorophyll reflects green light

Question 16

Which of the following is a real-world consequence of photorespiration in crop plants under hot, dry conditions?

Accepted Answer

Reduced yield due to loss of fixed carbon and energy

Question 17

Which of the following best explains why ATP and NADPH are needed for the Calvin cycle?

Accepted Answer

They provide energy and reducing power to convert $$CO_2$$ into G3P

Question 18

If a plant's rubisco enzyme is mutated so that it cannot bind $$CO_2$$, what will be the immediate effect on the Calvin cycle?

Accepted Answer

Carbon fixation will not occur, halting the cycle

Question 19

Which of the following is a correct comparison between chemiosmosis in mitochondria and chloroplasts?

Accepted Answer

Both use a proton gradient to drive ATP synthesis via ATP synthase

Question 20

A scientist wants to increase the rate of photosynthesis in a greenhouse. Which of the following changes would be most effective?

Accepted Answer

Increasing the concentration of $$CO_2$$

Photosynthesis: Mechanisms and Importance in Plants (Chapter 10 Study Notes)

Study Guide - Practice Questions

Study Guide - Flashcards