C₄ -plants are more efficient in photosynthesis than C₃ -plants due to 

1. higher leaf area

2. presence of larger number of chloroplasts in the leaf cells. 

3. presence of thin cuticle

4. lower rate of photorespiration

Cyclic-photophosphorylation results in the formation of 

1. NADPH

2. ATP and NADPH

3. ATP, NADPH and O₂

4. ATP

THe C₄ -plants are photosynthetically more efficient than C₃ -plants because

(1) the CO₂ compensation point is more

(2) CO₂ generated during photorespiration is trapped and recycled through PEP carboxylase

(3) the CO₂ efflux is not prevented

(4) they have more chloroplasts.

Electrons from excited chlorophyll molecule of photosystem-II are accepted first by

1. cytochrome-b

2. cytochrome-f

3. quinone

4. ferredoxin

In the leaves of C₄ -plants malic acid synthesis during CO₂ fixation occurs in 

(1) epidermal cells

(2) mesophyll cells

(3) bundle sheath

(4) guard cells

Carbohydrates are commonly found as starch in plant storage organs. Which of the

following five properties of starch (A-E) make it useful as a storage material?

(A) Easily translocated 

(B) Chemically non-reactive

(C) Easily digested by animals

(D) Osmotically inactive

(E) Synthesized during photosynthesis

The useful properties are 

1. (B) and (C)

2. (B) and (D)

3. (A), (C) and (E)

4. (A) and (E)

The wavelength of light abosorbed by P_r form of phytochrome is :

(1) 640 nm

(2) 680 nm

(3) 720 nm

(4) 620 nm

In photosystem-I, the first electron acceptor is :

(1) ferredoxin

(2) cytochrome

(3) plastocyanin

(4) an iron-sulphur protein

During photorespiration, the oxygen consuming reaction(s) occur in :

(1) stroma of chloroplasts and mitochondria

(2) stroma of chloroplasts and peroxisomes

(3) grana of chloroplasts and peroxisomes

(4) stroma of chloroplasts

Photorespiration is favoured by

(1) high O₂ and low CO₂ concentration

(2) low O₂ and high CO₂ concentration

(3) low light intensity

(4) low temperature.