Highlight the differences between the population interactions given below. Give an example of each.

(a) Parasitism

(b) Amensalism

(c) Mutualism

One of the twins born to parents having normal colour vision was colour blind whereas the other twin had normal vision. Work out the cross. Give two reasons how it is possible.

How do fossils help us in understanding the evolutionary history?

(a) Geitonogamy and xenogamy, both require pollinating agents, yet they are very different from each other. Explain how.

(b) Describe the characteristics of flowers that are pollinated by wind.

OR

Explain the process of development of a mature human female gamete from the time it is initiated till the formation of ootid.

Name the condition in vertebrates where the body attacks self-cells.