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

Production of NADPH in a chloroplast takes place during

1. cyclic photophosphorylation

2. non-cyclic photophosphorylation

3. series photophosphorylation

4. substrate level photophosphorylation.

The photoautotrophic organisms that do not split water to obtain reducing power are 

(1) purple bacteria 

(2) cyanobacteria

(3) green plants

(4) none of these

Dark reaction occurs

(1) only in light

(2) only in the absence of light

(3) independent of light

(4) both (1) and (3).

Photorespiration, usually occurs in

(1) one cell organelle

(2) two cell organelles

(3) three cell organelles

(4) four cell organelles.

Which of the following statements about phytochrome is true?

1. P_r absorbs yellow light and becomes P_fr 

2. P_r absorbs red light and becomes P_fr 

3. P_fr absorbs red light and becomes P_r 

4. P_fr absorbs yellow light and becomes P_r .