What is the function of the trachea? Why do its walls not collapse even when there is less air in it?

When does anaerobic respiration occurs in our body? Give an example.

Name the plant hormone which helps in stomata opening?

Give an Example of a plant in which stomata is absent?

A, Band Care three living organisms. The organism A is a unicellullar fungus which can live without air. It is used in the commercial production of an organic compound P from molasses. The organism B is a unicellular animal which lives in water and feeds and moves by using pseudopodia. It breathes through an organelle Q. The organism C is a tiny animal which acts as a carrier of malarial parasite. It breathes and respires through a kind of tiny holes Rand air-tubes Sin its body.

(a) What are organisms (i) A (ii) B, and (iii) C?

(b) Name (i) P (ii) Q (iii) R, and (iv) S.

(c) Which organism/ organisms undergo aerobic respiration?

(d) Which organism/ organisms undergo anaerobic respiration?

Give two major differences between epidermal and guard cells.