In the C4 pathway, which of the following molecules combines with carbon dioxide?

1. glyceraldehyde phosphate

2. ribulose biphosphate

3. phosphoenol pyruvic acid

4. citric acid

Crops such as tomatoes and bell pepper, allowed to grow in a carbon dioxide rich environment, show higher yields because:

A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilization. In which of the following physiological groups would you assign this plant?

(1) C₄

(2) CAM

(3) Nitrogen-fixer

(4) C₃

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.

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 C₄ plants grow very efficiently in warm climates because they

(1) consume fewer ATP molecules for glucose synthesis

(2) minimize photorespiratory losses

(3) have more efficient chloroplasts

(3) contain enzymes which are not inactivated at high temperatures.

Kranz anatomy is usually associated with 

(1) C₃ plants

(2) C₄ plants

(3) CAM plants

(4) C₃-C₄ intermediate plants.

C₄ plants have better productivity because 

(1) C₄ plants absorb more light

(2) C₄ plants absorb more CO₂

(3) C₄ plants does not carry photorespiration

(4) C₄ plants have more amount of RuBisCO.

Kranz anatomy can be observed in leaves of:

1. sorghum

2. spinach

3. mustard

4. tulip