Our fore arm is made of three different bones. Comment.

The following diagrams are the age pyramids of different populations. Comment on the status of these populations.

How is it advantageous for an organism to be made of different kinds of cells instead of one kind?

There are unlimited number of identical balls of three different colours. How many arrangements of atmost 7 balls in a row can be made by using them? (a) 2187 (b) 343 (c) 399 (d) 3279

What are gums made of? Is Fevicol different?

Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions. Comment.

The body of sponges does not possess tissue level of organisation though it is made of thousands of cells. Comment.