Question 1

Which of the following best describes the role of autotrophs in an ecosystem?

Accepted Answer

They produce organic molecules from inorganic substances using sunlight.

Question 2

What is the overall balanced chemical equation for photosynthesis in plants?

Accepted Answer

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

Question 3

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

Accepted Answer

Thylakoid membrane

Question 4

During the light-dependent reactions of photosynthesis, what is the immediate source of electrons for the electron transport chain?

Accepted Answer

Water ($$H_2O)$$

Question 5

Which of the following is a product of the light-dependent reactions that is directly used in the Calvin Cycle?

Accepted Answer

ATP

Question 6

What is the primary function of the enzyme Rubisco in photosynthesis?

Accepted Answer

Fixing carbon dioxide to ribulose-1,5-bisphosphate (RuBP)

Question 7

Which of the following statements correctly compares chemiosmosis in mitochondria and chloroplasts?

Accepted Answer

In mitochondria, protons are pumped into the intermembrane space; in chloroplasts, into the thylakoid space.

Question 8

Which pigment is primarily responsible for the green color of leaves and the absorption of blue and red light?

Accepted Answer

Chlorophyll a

Question 9

In the Calvin Cycle, what is the fate of most glyceraldehyde-3-phosphate (G3P) molecules produced?

Accepted Answer

They are recycled to regenerate RuBP.

Question 10

Which of the following best explains why plants appear green?

Accepted Answer

Chlorophyll reflects green light and absorbs blue and red light.

Question 11

Which process occurs when plants close their stomata in hot, arid climates, leading to a buildup of oxygen and a decrease in photosynthetic efficiency?

Accepted Answer

Photorespiration

Question 12

Which of the following is true about C4 plants compared to C3 plants?

Accepted Answer

C4 plants separate CO$$_2$$ intake from the Calvin Cycle spatially.

Question 13

What is the main advantage of CAM plants in arid environments?

Accepted Answer

They fix CO$$_2 at $$night and perform the Calvin Cycle during the day.

Question 14

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

Accepted Answer

Glyceraldehyde-3-phosphate (G3P)

Question 15

Which molecule is oxidized and which is reduced during photosynthesis?

Accepted Answer

H$$_2O is $$oxidized; CO$$_2 is $$reduced.

Question 16

Which of the following is NOT a substrate for the light-dependent reactions of photosynthesis?

Accepted Answer

CO$$_2$$

Question 17

What is the main purpose of cyclic electron flow in photosynthesis?

Accepted Answer

To produce ATP only

Question 18

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

Accepted Answer

Photosynthesis stores energy in glucose; respiration releases it as ATP.

Question 19

A scientist exposes a filament of algae to different wavelengths of light and observes the distribution of oxygen-seeking bacteria. What does this experiment demonstrate?

Accepted Answer

Photosynthesis is most efficient at wavelengths where oxygen is produced.

Question 20

Which of the following is a correct summary of the products of the light-dependent reactions that are utilized in the Calvin Cycle?

Accepted Answer

ATP and NADPH

Chapter 8: Photosynthesis – Structure, Function, and Ecological Role

Guida di studio - Domande di pratica

Study guide - Flashcard