Question 1

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

Accepted Answer

$$6 \ \mathrm{CO}_2 + 6 \ \mathrm{H}_2\mathrm{O} \rightarrow C_6H_{12}O_6$ + 6 \ \mathrm{O}_2$$

Question 2

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

Accepted Answer

To regulate gas exchange by allowing $$\mathrm{CO}_2 in $$and $$\mathrm{O}_2$$ out

Question 3

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

Accepted Answer

Thylakoid membrane

Question 4

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

Accepted Answer

Photosynthesis will decrease because chlorophyll reflects green light rather than absorbing it.

Question 5

Which of the following best describes the role of ATP and NADPH in photosynthesis?

Accepted Answer

They provide energy and reducing power for the Calvin Cycle to synthesize carbohydrates.

Question 6

During the light-dependent reactions, what is the source of electrons that are ultimately used to reduce NADP$$^+ to $$NADPH?

Accepted Answer

Water ($$\mathrm{H}_2\mathrm{O})$$

Question 7

Which of the following is NOT a direct input for the Calvin Cycle (light-independent reactions)?

Accepted Answer

Oxygen ($$\mathrm{O}_2)$$

Question 8

A scientist measures the rate of photosynthesis in a crop field as atmospheric $$\mathrm{CO}_2$$ levels rise. Which of the following is most likely to occur initially?

Accepted Answer

The rate of photosynthesis will increase, as more $$\mathrm{CO}_2 is $$available for the Calvin Cycle.

Question 9

Which of the following best explains why plants appear green to the human eye?

Accepted Answer

Chlorophyll absorbs red and blue wavelengths and reflects green light.

Question 10

If a plant's thylakoid membranes were damaged, which process would be most directly affected?

Accepted Answer

The light-dependent reactions, including ATP and NADPH production

Question 11

Which of the following statements about the movement of energy in photosynthesis is correct?

Accepted Answer

Light energy is converted into chemical energy stored in the C-H bonds of glucose.

Question 12

A plant is placed in a sealed chamber with limited water but abundant light and $$\mathrm{CO}_2. $$Which process will be most directly limited?

Accepted Answer

The splitting of water to provide electrons for the light reactions

Question 13

Which of the following best describes the relationship between the light-dependent and light-independent reactions?

Accepted Answer

The light-dependent reactions produce ATP and NADPH, which are used by the Calvin Cycle to fix $$\mathrm{CO}_2.$$

Question 14

If the stomata of a plant are closed during a hot, dry day, what is the most immediate consequence for photosynthesis?

Accepted Answer

Reduced $$\mathrm{CO}_2$$ uptake, limiting the Calvin Cycle

Question 15

Which of the following is a direct output of the Calvin Cycle?

Accepted Answer

G3P (glyceraldehyde-3-phosphate)

Question 16

A researcher increases the temperature in a greenhouse. Which of the following is a likely effect on photosynthesis in crop plants, assuming all other factors are optimal?

Accepted Answer

Photosynthesis will increase up to an optimal temperature, then decrease as enzymes denature.

Question 17

Which of the following best explains why ATP is required during the Calvin Cycle?

Accepted Answer

ATP provides the energy needed to convert 3-phosphoglycerate into G3P.

Question 18

Which of the following is true regarding the electromagnetic spectrum and photosynthesis?

Accepted Answer

Photosynthetic pigments absorb primarily visible light, especially red and blue wavelengths.

Question 19

A mutation causes a plant to lack functional NADP$$^+$$ reductase. What is the most immediate effect on photosynthesis?

Accepted Answer

The plant cannot produce NADPH, limiting the Calvin Cycle.

Question 20

Which of the following scenarios would most likely result in a decrease in crop production due to climate change?

Accepted Answer

Sustained high temperatures causing enzyme denaturation in photosynthetic pathways

Study Notes: Photosynthesis (Chapter 7)

Study Guide - Practice Questions

Study Guide - Flashcards