The bundle sheath cells are characterized by:

I:	a large number of chloroplasts present in them
II:	thick cell walls impervious to gas exchange
III:	large intercellular spaces

1. Only I and II	2. Only I and III
3. Only II and III	4. I, II and III

The primary ${\mathrm{CO}}_2$ acceptor in ${\mathrm{C}}_4$ plants is:
1. RuBP in mesophyll cells
2. RuBP in bundle sheath cells
3. PEP in mesophyll cells
4. PEP in bundle sheath cells

The ${\mathrm{C}}_3$ pathway:
1. is common to all plants
2. takes place in mesophyll cells in ${\mathrm{C}}_4$ plants
3. takes place in bundle sheath cells in ${\mathrm{C}}_3$ plants
4. does not take place in CAM plants

In ${\mathrm{C}}_4$ pathway, the 4-carbon compound transported to bundle sheath cells most commonly is:

The most common enzyme in the world is:

The 2-carbon compound formed in photorespiration is:

Photorespiration is a wasteful process. Why is it so?

Identify the correctly matched rows:

Except for plants in shade or in dense forests, light is rarely a limiting factor in nature. This is because:

Which pigment acts directly to convert light energy to chemical energy ?