CBSE Class 12 Biology Solved Question Paper 2018

Name two diseases whose spread can be controlled by the eradication of Aedes mosquitoes.

How do cytokine barriers provide innate immunity in humans?

Your advice is sought to improve the nitrogen content of the soil to use for cultivation of a non-leguminous terrestrial crop.

(a) Recommend two microbes that can enrich the soil with nitrogen.

(b) Why do leguminous crops not require such enrichment of the soil?

Name the source plants of heroin drug. How is it obtained from the plants?

You have obtained a high yielding variety of tomato. Name and explain the procedure that ensures retention of the desired characteristics repeatedly in large populations of future generations of the tomato crop.

Write the names of the following :
(a) A 15 mya primate that was ape-like
(b) A 2 mya primate that lives in East African grasslands

How did a citizen group called Friends of Arcata Marsh, Arcata, California, USA, help to improve water quality of the marshland using Integrated Waste Water Treatment ? Explain in four steps.

Write the effects of heroin on the human body.

Write the dual purpose served by Deoxyribonucleoside triphosphates in the polymerisation.

Mention the chemical change that proinsulin undergoes, to be able to act as mature insulin.