In photosystem-I, the first electron acceptor is :
(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 photorepsiratory 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.
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
(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. 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 .