The part of P and Q are present only in plant cells, and they are not present in animal cells. The part P contains a green pigment called R whereas part Q is made of a tough material S. The part P takes part in the food making process whereas part Q gives shape and support to the plant cell.
(a) What is (i) P, and (ii) Q?
(b) What is (i) R, and (ii) S?
(a) (i) The part P is Chloroplasts
Chloroplasts are the food producers in plant cells and they are not present in animal cells because animal cells do not make their own food.
(ii) The part Q is Cell wall
The cell wall is absent in the animal cells because they don't need cell walls. The main purpose of a cell wall is to provide stability and stiffness to the cell. And it is made up of cellulose.
(b) (i) The part R is Chlorophyll
Chlorophyll is the green pigment present in the leaves.
(ii) The part S is Cellulose
Cellulose is a fiber and wood, cotton, etc. all contain cellulose.