All the following regarding the role of xanthophylls and carotenoids in photosynthesis are correct except:
| 1. | They act as accessory pigments |
| 2. | Their peak absorption is in blue and red regions of VIBGYOR |
| 3. | They enable a wider range of wavelength of incoming light to be utilized for photosynthesis |
| 4. | They protect chlorophyll a form of photo-oxidation. |
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 Pr 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. | Pr absorbs yellow light and becomes Pfr |
| 2. | Pr absorbs red light and becomes Pfr |
| 3. | Pfr absorbs red light and becomes Pr |
| 4. | Pfr absorbs yellow light and becomes Pr . |
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. |
In blue-green algae, photosystem- II contains important pigment concerned with photolysis of water. It is a
1. phycocyanin
2. cytochrome-c
3. chlorophyll -
4. -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. |
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