Study the diagram given below and match the structure with its function:

Explain the term Menarche.

Ayush was in the final round of a carrom match. He was focussing intently on the strokes of the opponent player.

(a) Which part of the brain helps Ayush to focus on the game?

(b) Name the part of the brain that co-ordinates his muscles while using the striker.

State the permeability of cell membrane and cell wall.