Question

Spot the incorrect statement about the exchange of gases in animals.

• A. Fishes have a counter-current exchange of gases
• B. Molluscs use gills whereas earthworms use moist skin for respiration
• C. Frogs respire through skin and lungs
• D. Cockroaches have blood that helps primarily in gaseous transport

Answer 1

The correct option is D

Cockroaches have blood that helps primarily in gaseous transport

The correct option is D.

Explanation of correct option:

Option D:

1. The respiratory system of the cockroach includes several tube-like structures known as the trachea.
2. They have openings at the surface of the thorax and abdomen.
3. These openings are called spiracles.

Explanation of incorrect options:

Option A:

1. The countercurrent mechanism is the mechanism in which the oxygen enters the blood of the fishes from water.
2. In this, the blood flows opposite to the water.

Option B:

1. Molluscs breathe through the gills. Their gills are comb-like in shape.
2. Breathing in the earthworms is achieved by their moist skin.

Option C:

1. Frogs are amphibians. They can live in water as well as on land.
2. Hence, they have both lungs and gills to breathe.

Final answer: The incorrect pair is cockroaches have blood that helps primarily in gaseous transport.