${\mathrm{C}}_4$ -plants are photosynthetically more efficient than ${\mathrm{C}}_3$ -plants because
1. ${\mathrm{CO}}_2$ compensation point is more.
2. ${\mathrm{CO}}_2$ generated during photorespiration is trapped and recycled through PEP carboxylase.
3. ${\mathrm{CO}}_2$ efflux is not prevented.
4. they have more chloroplasts.

In the leaves of ${\mathrm{C}}_4$ -plants, malic acid synthesis during ${\mathrm{CO}}_2$ fixation occurs in
1. epidermal cells
2. mesophyll cells
3. bundle sheath
4. guard cells

Carbohydrates are commonly found as starch in plant storage organs. Which of the following five properties of starch (A-E) make it useful as a storage material?
A. Easily translocated
B. Chemically non-reactive
C. Easily digested by animals
D. Osmotically inactive
E. Synthesized during photosynthesis
The useful properties are
1. (B) and (C)
2. (B) and (D)
3. (A), (C) and (E)
4. (A) and (E)

The first acceptor of electrons from an excited chlorophyll molecule of photosystem II is :

In photosystem-I, the first electron acceptor is :

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

The first step for initiation of photosynthesis will be
1. Photolysis of water
2. Excitement of chlorophyll molecule due to absorption of light
3. ATP formation
4. Glucose formation

In sugarcane plant,${}^{14}\mathrm{CO}_2$ is fixed in malic acid in which the enzyme that fixes ${\mathrm{CO}}_2$ is
1. Ribulose biphosphate carboxylase
2. Phosphoenol pyruvic acid carboxylase
3. Ribulose phosphate kinase
4. Fructose phosphatase

As compared to a ${\mathrm{C}}_3$ plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by ${\mathrm{C}}_4$ plants ?

Photosynthesis in ${\mathrm{C}}_4$ plants is relatively less limited by atmospheric ${\mathrm{CO}}_2$ levels because
1. The primary fixation of ${\mathrm{CO}}_2$ is mediated via PEP carboxylase.
2. Effective pumping of ${\mathrm{CO}}_2$ into bundle sheath cells.
3. Four carbon acids are the primary initial ${\mathrm{CO}}_2$ fixation products.
4. RuBisCO in ${\mathrm{C}}_4$ plants has higher affinity for ${\mathrm{CO}}_{2.}$