Photosynthesis in Higher Plants Chapter-Wise Test 13

Correct answer Carries: 4.

Wrong Answer Carries: -1.

What is the primary function of the proton gradient in photosynthesis?

ATP synthesis
Glucose formation
NADPH reduction
Oxygen evolution
1

The proton gradient drives ATP synthesis via ATP synthase in the thylakoid membrane.

Which factor has the most significant effect on the rate of photosynthesis in nature?

Oxygen availability
Carbon dioxide concentration
Glucose availability
Chlorophyll concentration
2

Carbon dioxide concentration is the most limiting factor for photosynthesis in natural conditions.

What is the primary function of Photosystem II in photosynthesis?

ATP synthesis
NADPH formation
Splitting of water to release oxygen
Fixation of CO₂
3

Photosystem II is responsible for the photolysis of water, which releases oxygen, protons, and electrons.

What is the primary role of plastocyanin in the electron transport chain?

Transports electrons from PSII to PSI
Pumps protons into the lumen
Synthesizes ATP
Fixes CO₂ in the Calvin cycle
1

Plastocyanin transfers electrons from the cytochrome b6f complex to PSI in the light-dependent reactions of photosynthesis.

Which of the following correctly describes the role of NADPH in photosynthesis?

It captures light energy.
It acts as a reducing agent in the Calvin cycle.
It splits water molecules.
It synthesizes ATP directly.
2

NADPH provides reducing power to convert carbon dioxide into glucose in the Calvin cycle.

Which compound is transported from the mesophyll to the bundle sheath cells in the C₄ pathway?

PGA
Malate
G3P
RuBP
2

In C₄ plants, malate is transported from mesophyll cells to bundle sheath cells, where it releases CO₂ for the Calvin cycle.

In CAM plants, carbon dioxide is fixed:

During the day
At night
Only in the morning
In bundle sheath cells
2

CAM plants fix CO2 at night and store it as organic acids to minimize water loss.

How many ATP molecules are required to fix one CO₂ molecule in the Calvin cycle?

1
2
3
6
3

The fixation of one CO₂ molecule in the Calvin cycle requires 3 ATP molecules.

Why do CAM plants keep their stomata closed during the day?

To prevent oxygen loss
To reduce transpiration
To increase CO₂ uptake
To perform photorespiration
2

CAM plants keep their stomata closed during the day to minimize water loss through transpiration in arid environments.

Which of the following statements about the Z-scheme of electron transport is correct?

Electrons flow from NADPH to water.
It involves both Photosystem I and II.
Oxygen is not released during this process.
ATP is not generated in this process.
2

The Z-scheme describes the linear flow of electrons from water to NADP+ via Photosystem II and Photosystem I.

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