Which one of the following acids is a derivative of carotenoids?
Indole butyric acid
Indole -3-acetic acid
Gibberellic acid
Gibberellic acid
Cyclic-photophosphorylation results in the formation of
NADPH
ATP and NADPH
ATP, NADPH and O2
ATP, NADPH and O2
D.
ATP, NADPH and O2
Cyclic-photophosphorylation involves only pigment system-I. When the photons activate PS-I, a pair of the electron are raised to a higher energy level. They are captured by the primary acceptor, which passes them on to ferredoxin, plastoquinone, cytochrome complex, plastocyanin and finally back to reaction centre of PS-I ie, P700. At each step of electron transfer, the electrons lose potential energy. Their trip downhill is caused by the transport chain to pump H+ across the thylakoid membrane. The proton gradient thus established is responsible for forming ATP ( 2 molecules). No reaction of NADP to NADPH + H+.
The C-4 plants are photosynthetically more efficient than C-3 plants because
the CO2 compensation point is more
CO2 generated during photorespiration is trapped and recycled through PEP carboxylase
the CO2 efflux is not prevented
the CO2 efflux is not prevented
The slow rate of decomposition of fallen logs in nature is due to their
low moisture content
poor nitrogen content
anaerobic environment around them
anaerobic environment around them
Which one of the following is resistant to enzyme action?
Cork
Wood fibre
Pollen exine
Pollen exine
In the leaves of C4 plants, malic acid formation during CO2 fixation occurs in the cells of
mesophyll
bundle sheath
phloem
phloem
The first acceptor of electrons from an excited chlorophyll molecule of photosystem II is
cytochrome
iron-sulphur protein
ferredoxin
ferredoxin
A plant requires magnesium for
holding cells together
protein synthesis
chlorophyll synthesis
chlorophyll synthesis
In photosystem-I, the first electron acceptor is
Ferredoxin
Cytochrome
Plastocyanin
Plastocyanin
During photorespiration, the oxygen-consuming reaction(s) occur in
stroma of chloroplasts and mitochondria
stroma of chloroplasts and peroxisomes
grana of chloroplasts and peroxisomes
grana of chloroplasts and peroxisomes