Assertion : The efficiency of C₄ plant is more than those of C₃ plant.

Reason : C₄ plants are more efficient in picking CO₂.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are hue but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Cyclic photophosphorylation involves

• PS I

• PS II

• PS I and PS II

• P₆₈₀

The first stable product of Calvin cycle is

• 3- phosphoglycerate

• 1, 3 biphosphoglycerate

• glyceralydehyde - 3 phosphate

• ribulose - 5 - phosphate

Assertion : Due to pollution atmospheric concentration of CO₂ is increasing which will be harmful for C₄ plants whereas productivity is going to increase for C₃ plants.

Reason : C4 plants have greater efficiency for CO₂ as CO₂ is fixed by PEP oxygenase.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

195.

PS-II occurs only in

• stroma

• granal thylakoids

• stromal lamella

• matrix

Which of the following statements is correct

• Photorespiration is useful process.

• C₄ plants are more efficient than C₃ plants.

• C₃ plants are more efficient than C₄ plants.

• Photorespiration is absent in C₃ plants but present in C₄ plants.

Which of the following is the characteristic of PS-I?

• It is active only upto 680 nm of light.

• The reaction centre of PS- I is P₆₈₀.

• PS- I is reduced by the electrons released in photolysis of water.

• PS-I is involved in non-cyclic photophosphorylation.

Assertion : Dark reaction occurs only at night in the stroma of chloroplast.

Reason : CO₂ fixation occurs only during C₃ cycle.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

In succulent plants the stomata open in night and close in day. Which among the following would be best hypothesis to explain the mechanism of stomatal action in night only.

• CO₂ accumulates, reduces pH, stimulate enzymes resulting in accumulation of sugars.

• Increase in CO₂ concentration, conversion of organic acids into starch resulting in the increased conversion into sugars resulting in K⁺ transport.

• Low CO₂ concentration accumulates organic acids resulting in the increased concentration of cell sap.

• CO₂ used up, increase pH results in accumulation of sugars.

Chlorenchyma is known to develop in the

• cytoplasm of Chlorella

• mycelium of a green mould such as Aspergillus

• spore capsule of a moss

• pollen tube of Pinus