(a) State the hypothesis which S.L. Miller tried to prove in the laboratory with the help of the set up given above.
(b) Name the organic compound observed by him in the liquid water after running the above experiment.
(c) A scientist simulated a similar set up and added CH₄, NH₃ and water vapour at 800°C.
Which important component is missing in his experiment?

The forelimbs of four vertebrates are shown in the diagram shown above.
(a) What type of evolution is exhibited by the similarity among these organs in those organisms?
(b) What are such organs known as?
(c) What do they indicate?

In 1950s, there were hardly any mosquitoes in Delhi. The use of the pesticide, DDT on standing water
killed their larvae. But, now there are mosquitoes because they have evolved DDT-resistance through the interaction of mutation and Natural selection. State in a sequences, how that could have happened.

When the reptiles came down, mammals took over the earth. There were mammals in South America, which resembled some of the modern day mammals. But due to continental drift, they disappeared whereas the pouched mammals of Australia flourished and evolved into the various forms of pouched mammals that we see today.
(a) Mention two characteristic features that were the reasons for the successful existence of mammals on earth.
(b) Why did the continental drift affect the mammals of South America and Australia, differently.

According to Hardy-Weinberg principle, the allele frequencies in a population are stable and remain constant through generations. When the frequency differs from the expected values, the difference indicates the extent (direction) of evolutionary change. Disturbance in the genetic equilibrium or Hardy-Weinberg equilibrium in a population can be interpreted as resulting in evolution.
(a) Write the algebraic equation representing Hardy-Weinberg equilibrium.
(b) List the five factors that affect the genetic equilibrium.