Figure 13.10 shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following questions:

(a) At which point/s (A, B or C) in the curve is light a limiting factor?

(b) What could be the limiting factor/s in region A?

(c) What do C and D represent on the curve?

Give comparison between C₃ and C₄ pathways.

Give comparison between anatomy of leaf in C₃ and C₄ plants.

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

• C₄

• CAM

• Nitogen-fixer

• Nitogen-fixer

Emerson's enhancement effect and red drop have instrumental in the discovery of

• two photosystems operating simultaneously

• photophosphorylation and cyclic electron transport

• oxidative phosphorylation

• oxidative phosphorylation

Specialised epidermal cells surrounding the guard cells are called

• sunbsidiary cells

• bulliform cells

• lenticels

• lenticels

109.

The three boxes in this diagram represent the three major biosynthetic pathways in aerobic net reactant or products



Arrows numbered 4, 8 and 12 can all be

• NADH

• ATP

• H₂O

• H₂O

Chromatophores take part in

• Photosynthesis

• Growth

• Movement 

• Movement