Photosynthesis in Higher Plants

Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because

1. effective pumping of CO2 into bundle sheath cells
2. RuBisCo in C4 plants has higher affinity for CO2
3. four carbon acids are the primary initial CO2 fixation products
4. the primary fixation of CO2 is mediated via PEP carboxylase.

Chlorophyll in chloroplasts is located in

1. Stroma
2. Grana
3. Pyrenoid
4. Both (1) and (3)

Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on

1. Proton gradient
2. Membrane potential
3. Accumulation of Na+ ions
4. Accumulation of K+ ions

In C3 plants, the first stable product of photosynthesis during the dark reaction is

1. malic acid
2. oxaloacetic acid
3. 3-phosphoglyceric acid
4. phosphoglyceraldehyde

Plants adapted to low light intensity have

1. larger photosynthetic unit size than the sun plants
2. higher rate of CO2 fixation than the sun plants
3. more extended root system
4. leaves modified to spines.

Which fractions of the visible spectrum of solar radiations are primarily absorbed by carotenoids of the higher plants?

1. Blue and green
2. Green and red
3. Red and violet
4. Violet and blue.

Which one of the following is wrong in relation to photorespiration?

1. It occurs in chloroplast
2. It occurs in day time only
3. It is a characteristic of C4 plants
4. It is a characteristic of C3 plants.

In sugarcane plant 14CO2 is fixed to malic acid, in which the enzyme that fixes CO2 is

1. ribulose bisphosphate carboxylase
2. phosphoenolpyruvic acid carboxylase
3. ribulose phosphate kinase
4. fructose phosphate.

Stomata of CAM plants

1. are always open
2. open during the day and close at night
3. open during the night and close during the day
4. never open.

Which element is located at the centre of the porphyrin ring in chlorophyll?

1. Calcium
2. Magnesium
3. Potassium
4. Manganese