Question

A, B and C are 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 R and air-tubes S in its body.

1. What are organisms (i) A (ii) B, and (iii) C?
2. Name (i) P (ii) Q (iii) R, and (iv) S.
3. Which organism/organisms undergo aerobic respiration?
4. Which organism/organisms undergo anaerobic respiration?

Answer 1

(a)

1. Organism A is yeast.
2. Organism B is an amoeba.
3. Organism C is mosquito.

(b)

1. P is ethanol (ethyl alcohol).
2. Q is the cell membrane because the amoeba breathes through the cell membrane.
3. R is spiracle.
4. S is tracheae.

(c) Organisms B (Amoeba) and C (Mosquito) undergo aerobic respiration because they require oxygen from their surroundings to completely break down food and generate high amounts of energy.

(d) Organism A (Yeast) undergoes anaerobic respiration because it can efficiently break down glucose and survive completely in the absence of oxygen.