question_answer

(a) State reason for the following:

(i) Rings of cartilage are present in the trachea.

(ii) Plants look green in colour.

(b) Write other names of the following:

(i) Alveolar sac

(ii) Voice box

Answer:

(a) (i)   Rings of cartilage are present in the trachea so that trachea does not collapse even when there is no air in it.

(ii) Plants look green in colour because of the presence of a green pigment called chlorophyll in it.

(b) (i) Alveolar sac \[\to \] Alveoli

(ii) Voice box \[\to \] Larynx