C4 -plants are more efficient in photosynthesis than C3 -plants due to
1. higher leaf area
2. presence of larger number of chloroplasts in the leaf cells.
3. presence of thin cuticle
4. lower rate of photorespiration
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
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
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 :
(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.