Science (English Medium) Class 12 - CBSE Important Questions for Biology

Write the difference between genetic biodiversity and species biodiversity that exists at all the levels of biological organisation.

Explain the formation of placenta after the implantation in a human female.

Describe the structure of a nucleosome.

Although a prokaryotic cell has no defined nucleus, yet DNA is not scattered throughout the cell. Explain.

Write the effects of heroin on the human body.

Describe the process of amplification of the “gene of interest” using the PCR technique.

Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.

Describe the structure of a seminiferous tubule.

Briefly describe the process of spermatogenesis.

Mention any three characteristics of Neanderthal man that lived in near east and central Asia.

Explain adaptive radiation with the help of a suitable example.

How is Hardy-Weinberg’s expression “(p² + 2pq + q²) = 1” derived?

List any two factors that can disturb the genetic equilibrium.

Write the scientific name of the source plant and the part from which opiods are extracted. What is it commonly and chemically called?

What are methanogens?

Describe how do 'flocs' and 'activated sludge' help in Sewage Treatment.

Why are baculoviruses considered good biocontrol agents?

Suggest two advantages to a farmer for using apomictic seeds of hybrid varieties.

Explain, giving three reasons, why tropics show greatest levels of species diversity.

Explain the post-pollination events leading to seed production in angiosperms.