With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?

(1) Light saturation for CO₂-fixation occurs at 10% of full sunlight.

(2) Increasing atmospheric CO₂ concentration upto 0.05% can enhance the CO₂-fixation rate

(3) C₃ plants respond to higher temperature with enhanced photosynthesis, while C₄ plants have a much lower temperature optimum.

(4) Tomato is a greenhouse crop, which can be grown in a CO₂-enriched atmosphere for higher yield. 

Phosphoenol pyruvate (PEP) is the primary CO₂ acceptor in:
1. C₄ plants
2. C₂ plants
3. C₃ and C₄ plants
4. C₃ plants

Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using the following options. 

1. Both process can happen together because the diffusion coefficient of water and CO₂ is different. 

2. The above processes happen only during night time

3. One process occurs during the day time and the other night

4. Both processes cannot happen simultaneously

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

The process which makes a major difference between C₃ and C₄ plants is:

Water-soluble pigments found in plant cell vacuoles are:

Emerson’s enhancement effect and red drop have been instrumental in the discovery of?