Distinguish between stoma and stroma.

Navya is a high school biology student who recently visited a local farm as part of a school project. She observed water droplets on the leaves of certain plants early in the morning as shown in the figure.

(a) Name the process observed.

(b) Explain the process mentioned in (a).

(c) Give the reason for the occurrence of the above-mentioned process.

Expand the following abbreviations:

(a) ACTH

(b) ABA

A basement godown is stocked with bags of food grains. It is observed that the walls of the godown cracked after being flooded with rain water. Explain the phenomenon.