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.

The C₄ plants grow very efficiently in warm climates because they

(1) consume fewer ATP molecules for glucose synthesis

(2) minimize photorespiratory losses

(3) have more efficient chloroplasts

(3) contain enzymes which are not inactivated at high temperatures.

Following is needed in the ionic form during non-cyclic photophosphorylation but not during cyclic photophosphorylations in higher plants. 

(1) copper

(2) iron

(3) manganese

(4) zinc