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

Question 1

Which of the following organisms are capable of performing oxygenic photosynthesis?

Accepted Answer

Plants, multicellular algae, and cyanobacteria

Question 2

Photosynthesis is classified as which type of reaction and metabolic process?

Accepted Answer

Endergonic and anabolic

Question 3

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

Accepted Answer

$$6CO_2 + 12H_2O + 	ext{light energy} ightarrow C_6H_{12}O_6$ + 6O_2 + 6H_2O$$

Question 4

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

Accepted Answer

Thylakoid membrane

Question 5

What is the main function of the pigment chlorophyll a in photosynthesis?

Accepted Answer

Absorbing light energy and transferring it to the reaction center

Question 6

Why do leaves appear green to the human eye?

Accepted Answer

Green wavelengths of light are reflected, while other wavelengths are absorbed

Question 7

Which wavelengths of visible light are most effective for driving photosynthesis, according to the absorption spectrum of chlorophyll a?

Accepted Answer

Violet-blue and red

Question 8

During the light reactions, what is the immediate source of electrons for Photosystem II (PSII)?

Accepted Answer

Water ($$H_2O)$$

Question 9

What is the main role of the cytochrome-b6f-complex (CBFC) in the light reactions of photosynthesis?

Accepted Answer

Pumping protons into the thylakoid lumen to create a proton gradient

Question 10

Which of the following best describes the function of ATP synthase in the chloroplast?

Accepted Answer

It uses the proton gradient to synthesize ATP from ADP and $$P_i$$

Question 11

What is the primary function of the Calvin Cycle in photosynthesis?

Accepted Answer

To fix inorganic carbon from $$CO_2$$ into organic sugars

Question 12

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

Accepted Answer

Rubisco

Question 13

What is photorespiration and why is it considered wasteful for C3 plants?

Accepted Answer

It occurs when rubisco binds to $$O_2$$ instead of $$CO_2$$, consuming ATP and releasing $$CO_2$$ without producing sugar

Question 14

How do C4 plants minimize photorespiration?

Accepted Answer

By separating initial $$CO_2$$ fixation and the Calvin Cycle in different cell types

Question 15

Which adaptation allows CAM plants to survive in hot, arid environments?

Accepted Answer

They separate $$CO_2$$ fixation and the Calvin Cycle by time, fixing $$CO_2 at $$night

Question 16

Which of the following is a correct comparison between cyclic and non-cyclic photophosphorylation?

Accepted Answer

Cyclic photophosphorylation produces only ATP, while non-cyclic produces both ATP and NADPH

Question 17

A plant is exposed to light that is only in the green wavelength range (around 550 nm). What is the most likely effect on the rate of photosynthesis?

Accepted Answer

The rate of photosynthesis will decrease because green light is mostly reflected, not absorbed

Question 18

Which of the following best explains why the cuticle is thicker on the upper surface of leaves?

Accepted Answer

To reduce water loss due to direct sunlight exposure

Question 19

What is the main function of stomata in plant leaves?

Accepted Answer

To regulate gas exchange and water loss

Question 20

Which vascular tissue is responsible for transporting water and minerals from roots to shoots in plants?

Accepted Answer

Xylem

Photosynthesis: Mechanisms, Adaptations, and Ecological Importance

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