All the following regarding the role of xanthophylls and carotenoids in photosynthesis are correct except:

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

1. cytochrome-b

2. cytochrome-f

3. quinone

4. ferredoxin

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

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 .

Photosynthetic bacteria do not contain

(1) quantasome

(2) PS-I and PS-II

(3) PS-I

(4) PS-II.

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

(1) It is activate only upto 680 nm of light.

(2) The reaction centre of PS-I is P₆₈₀ . 

(3) PS-I is reduced by the electrons released in photolysis of water.

(4) PS-I is involved in non-cyclic photophosphorylation.

PS-II occurs only in

(1) stroma

(2) granal thylakoids

(3) stromal lamella

(4) matrix

In blue-green algae, photosystem- II contains important pigment concerned with photolysis of water. It is a

(1) phycocyanin           

(2) cytochrome-c

(3) chlorophyll -$b$         

(4) $\beta$-carotene

Which of the following statement is incorrect?
1. Oxygen is released from water.
2. Photosynthesis is a single step reaction.
3. Action spectrum of photosynthesis resembles roughly the absorption spectra of chlorophyll a and b.
4. In plants glucose is stored as starch.