Photosynthesis in C₄ plants is relatively less limited by atmospheric CO₂ levels because

• there is effective pumping of CO₂ into bundle sheath cells

• RuBisCO in C4 plants has higher affinity for CO₂

• six carbon acids are the primary initial CO₂ fixation products

• the primary fixation of CO₂ is mediated via PEP carboxylase.

The chemiosmotic coupling hypothesis of oxidative phosphorylation proposes that adenosine triphosphate (ATP) is formed because

• a proton gradient forms across the inner mitochondrial membrane

• there is a change in the permeability of the inner mitochondrial membrane towards adenosine diphosphate (ADP).

• high energy bonds are formed in mitochondrial proteins

• ADP is pumped out of the matrix into the intermembrane space

183.

Carbon dioxide is necessary for photosynthesis. The chemical used to remove this gas most effectively from entering a control apparatus is

• calcium oxide

• distilled water

• potassium hydroxide solution

• sodium carbonate.

Assertion: In light reaction of photosynthesis, light is required for the functioning of PS I and PS II, and production of NADPH and ATP.

Reason: Dark reaction does not occur in light.

• 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.

Assertion : CAM plants lack structural compartmentation of leaf as found in C₄ plants.

Reason : Stomata of CAM plants are open during the day.

• 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

C₄ plants have better productivity because

• C₄ plants absorb more light

• C₄ plants absorb more CO₂

• C₄ plants does not carry photorespiration

• C₄ plants have more amount of RuBisCO

Assertion: Photorespiration interferes with the successful functioning of Calvin cycle.

Reason: Photorespiration oxidises ribulose1,5 biphosphate which is an acceptor of CO₂ in Calvin 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.

Photorespiration shows formation of

• sugar but not ATP

• ATP but not sugar

• both ATP and sugar

• neither ATP nor sugar

Which of the following is correctly labelled for the given figure

• A: PS II; B : PS I; C :e^- acceptor, D: LHC

• A: LHC; B:e^- acceptor; C: PS I; D: PS II

• A: PS I; B:PS II; C:e^- acceptor; D: LHC

• A: e^- acceptor; B : LHC; C: PS Il; D: PS I

Kranz anatomy is usually associated with

• C₃ plants

• C₄ plants

• CAM plants

• C₃-C₄intermediate plants.