Give reasons for:

Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuoles. 

Give reasons for

Intercellular spaces are absent in sclerenchymatous tissue.

Give reasons for:

We get a crunchy and granular feeling when we chew pear fruit.

Give reasons for:

Branches of a tree move and bend freely in high wind velocity.

Give reasons for:

It is difficult to pull out the husk of coconut.

When water is cooled to a temperature $\mathrm{x}$, it get converted into ice at temperature $\mathrm{x}$ by a process called $\mathrm{P}$ and then ice at temperature $\mathrm{x}$ is warmed. It gets re-converted into water at the same temperature $\mathrm{x}$ in a process called $\mathrm{Q}$.

(a) What is the value of temperature $\mathrm{x}$ in Kelvin scale?

(b) What is the process $\mathrm{P}$ known as?

(c) What is the name of energy released during process $\mathrm{P}$?

(d) What is the process $\mathrm{Q}$ known as?

(e) What is the name of energy absorbed during process $\mathrm{Q}$?