True/false
Hydra shows direct and body surface respiration.

Which animal groups shows body surface respiration?

Why do the higher animals not show body surface respiration?

True/false Frog shows only cutaneous respiration.

True/false As compared to aerobic respiration in anaerobic respiration less energy is produced.

State whether the following statement is true or false-"When a person walks on a rough surface,the frictional force exerted by the surface on the person is opposite to the direction of his motion".

True or False Aerobic respiration produces energy about 18 times than in anaerobic respiration.

True or false Plover and Crocodile show protocooperation