Why are human beings who look so different from each other in terms of size, colour and look said to belongs to the same species?

What are fossils? What do they tell us about the process of evolution?

Distinguish between acquired and inherited traits giving one example of each. Why are traits acquired during the lifetime of an individual not inherited?

Given below is the experiment carried out by Mendel to study inheritance of two traits in garden pea.

(i) Fill in the boxes with appropriate answer.

(ii) Why did Mendel carry out an experiment with two traits?

(iii) What were his findings with respect to inheritance of traits in F₁ and F₂ generations?

In human males, all the chromosomes are paired perfectly except one. This/these unpaired chromosome is/are”

(i) large chromosome

(ii) small chromosome

(iii) Y-chromosome

(iv) X-chromosome