Q: What is the overall chemical equation for photosynthesis?

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

Question 1

Which of the following best describes the role of autotrophs in the biosphere?

Accepted Answer

They produce organic molecules from CO2 and other inorganic molecules, serving as the ultimate source of organic compounds for all heterotrophic organisms.

Question 2

Which structure within the chloroplast is primarily responsible for capturing light energy during photosynthesis?

Accepted Answer

Thylakoid membrane

Question 3

What is the overall chemical equation for photosynthesis?

Accepted Answer

$$6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + 	ext{energy} ightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2$$

Question 4

Which of the following statements about the light reactions of photosynthesis is correct?

Accepted Answer

They split water, release O2, produce ATP and NADPH, but do not produce sugar.

Question 5

Why do leaves appear green to our eyes?

Accepted Answer

Chlorophyll reflects and transmits green light while absorbing other wavelengths.

Question 6

Which enzyme catalyzes the first step of carbon fixation in the Calvin cycle?

Accepted Answer

Rubisco (Ribulose bisphosphate carboxylase-oxygenase)

Question 7

What is the main adaptive advantage of C4 plants over C3 plants in hot, dry environments?

Accepted Answer

C4 plants spatially separate carbon fixation from the Calvin cycle, reducing photorespiration.

Question 8

Which of the following best explains why photorespiration is considered wasteful for C3 plants?

Accepted Answer

It consumes O2 and organic fuel without producing ATP or sugar.

Question 9

During the light reactions, what is the final electron acceptor in the linear electron flow pathway?

Accepted Answer

NADP+

Question 10

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

Accepted Answer

Both generate ATP using a proton gradient, but the source of electrons differs.

Question 11

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

Accepted Answer

Decreased CO2 uptake, increased O2 buildup, and increased photorespiration.

Question 12

Which pigment is the main photosynthetic pigment in plants, and what is its primary function?

Accepted Answer

Chlorophyll a; absorbs violet-blue and red light for energy capture.

Question 13

Which process occurs in the stroma of the chloroplast?

Accepted Answer

Calvin cycle (carbon fixation and sugar production)

Question 14

What is the role of accessory pigments such as chlorophyll b and carotenoids in photosynthesis?

Accepted Answer

They broaden the spectrum of light that can be used for photosynthesis and provide photoprotection.

Question 15

Which of the following best describes the difference between C4 and CAM plants?

Accepted Answer

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

Question 16

Which of the following is a direct product of the Calvin cycle?

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 17

If a plant is exposed only to green light, what would you expect to happen to its rate of photosynthesis?

Accepted Answer

It would decrease because green light is mostly reflected and not absorbed.

Question 18

Which of the following best explains why the Calvin cycle is considered an anabolic pathway?

Accepted Answer

It uses energy to build complex molecules from simpler ones.

Question 19

Which of the following is NOT a product of the light reactions of photosynthesis?

Accepted Answer

Glucose

Question 20

A scientist measures the rate of O2 production in a plant exposed to different wavelengths of light. Which concept is being investigated?

Accepted Answer

Action spectrum

Photosynthesis: Mechanisms, Adaptations, and Importance

Guida di studio - Domande di pratica

Study guide - Flashcard