Mammals have

• biconvex RBCs to increase the surface area

• biconcave RBCs to increase the surface area

• spherical RBCs to increase the surface area

• no RBCs

Water vascular system is the characteristic of which group of the following: 

“All vertebrates are chordates but all chordates are not vertebrates”. Justify the statement.

How important is the presence of air bladder in Pisces?

What are the modifications that are observed in birds that help them fly?

Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?

Segmentation in the body is first observed in which of the following

Match the following:

Prepare a list of some animals that are found parasitic on human beings.

In some animal groups, the body is found divided into compartments with at least some organs/ organ repeated. This characteristic feature is named

Given below are types of cells present in some animals. Which of the following cells can differentiate to perform different functions?