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

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

Question 1

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

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 chlorophyll a in photosynthesis?

Accepted Answer

To initiate the light-dependent reactions by absorbing light energy

Question 3

Why do leaves appear green to the human eye?

Accepted Answer

Chlorophyll reflects green wavelengths of light

Question 4

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

Accepted Answer

Thylakoid membrane

Question 5

During the light-dependent reactions, what is the role of the electron transport chain (ETC)?

Accepted Answer

To create a proton gradient that drives ATP synthesis

Question 6

Which of the following best explains why C4 and CAM plants are more efficient in hot, dry environments than C3 plants?

Accepted Answer

They minimize photorespiration and water loss by altering the timing or location of carbon fixation

Question 7

What is the main product of the Calvin (C3) cycle that is used to form carbohydrates?

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 8

Which pigment is responsible for absorbing light primarily in the blue and red regions of the visible spectrum?

Accepted Answer

Chlorophyll a

Question 9

What is the main adaptive advantage of CAM photosynthesis?

Accepted Answer

It allows plants to fix carbon dioxide at night, reducing water loss during the day

Question 10

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

Accepted Answer

It uses ATP and NADPH produced in the light-dependent reactions to fix carbon dioxide

Question 11

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

Accepted Answer

The rate of photosynthesis will decrease because chlorophyll reflects green light

Question 12

Which of the following best describes photorespiration?

Accepted Answer

A process where oxygen is taken up and carbon dioxide is released, reducing photosynthetic efficiency

Question 13

What is the main function of stomata in plant leaves?

Accepted Answer

To allow gas exchange between the plant and the atmosphere

Question 14

Which of the following is a direct product of the light-dependent reactions of photosynthesis?

Accepted Answer

ATP and NADPH

Question 15

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

Accepted Answer

The synthesis of ATP and NADPH during the light-dependent reactions

Question 16

Which of the following best explains the role of accessory pigments like carotenoids in photosynthesis?

Accepted Answer

They absorb wavelengths of light not absorbed by chlorophyll and transfer the energy to chlorophyll a

Question 17

A scientist measures the rate of photosynthesis in a plant under different wavelengths of light. The rate is highest under red and blue light, but lowest under green light. Which graph best represents this result?

Accepted Answer

A graph with two peaks at approximately 450 nm (blue) and 680 nm (red), and a trough around 550 nm (green)

Question 18

Which of the following is a key difference between the C4 and CAM pathways?

Accepted Answer

C4 plants separate carbon fixation and the Calvin cycle spatially, while CAM plants separate them temporally

Question 19

Which of the following best describes the fate of water molecules during the light-dependent reactions of photosynthesis?

Accepted Answer

Water is split to provide electrons, protons, and oxygen gas

Question 20

A plant closes its stomata on a hot, dry day. What is the most immediate consequence for photosynthesis?

Accepted Answer

CO2 cannot enter the leaf, causing a decrease in the rate of photosynthesis

Photosynthesis: Mechanisms, Pigments, and Adaptations

Guida di studio - Domande di pratica

Study guide - Flashcard