Question

(a) How do guard cells regulate opening and closing of stomatel pores?
(b) Two similar green plants are kept separately in oxygen free containers, one in dark and the other in continuous light. Which one will live longer? Give reasons.

Answer 1

(a) When water flows into the guard cells, they swell and become curved. This causes the stomatal pore to open. On the other hand, when the guard cells lose water, they shrink and this cause the pore to close.

(b) The plant kept in continuous light will live longer as the leaves of the plants will be able to make food for the plant through photosynthesis. However, in the absence of light, the leaves will not be able to make food. This is because photosynthesis will not take place in the absence of light. Hence, the plant kept in dark will live shorter as compared to the plant kept in light.