Lack of relaxation between successive stimuli in sustained muscle contraction is known as?

1. fatigue
2. tetanus
3. tonus
4. spasm

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 processes can happen together because the diffusion coefficient of water and CO2 is different
2.	The above processes happen only during the night-time.
3.	One process occurs happen only in the daytime and the other at night
4.	Both processes cannot happen simultaneously

Cotyledon of maize grain is called?

1. coleorhizae
2. coleoptile
3. scutellum
4. plumule