Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Make a chart (with diagrammatic representation) showing restriction enzyme, the substrate DNA on which it acts on, the site at which it cuts DNA the product.

Write the scientific name of the fruit–fly. Why did Morgan prefer to work with fruit–flies for his experiments? State any three reasons.

Your advice is sought to improve the nitrogen content of the soil to be used for cultivation of a non-leguminous terrestrial crop:

1. Recommend two microbes that can enrich the soil with nitrogen.
2. Why do leguminous crops not require such enrichment of the soil?

In a dihybrid cross white eyed, yellow bodied female Drosophila crossed with red eyed, brown bodied male Drosophila produced in F₂ generation, 1.3 per cent recombinants and 98.7 per cent progeny with parental type combinations. This observation of Morgan deviated from Mendelian F₂ phenotypic dihybrid ratio. Explain, giving reasons, Morgan’s observations.

How does the HIV breakdown the immune system of the AIDS patient?

Fill in the blank (i), (ii), (iii), (iv) with name of the mammals of Australia.

S. No	Placental mammal	Marsupial mammal
(i)	Anteater	(i)
(ii)	(ii)	Spotted cuscus
(iii)	Bob cat	(iii)
(iv)	(iv)	Tasmanian wolf

What is double fertilization?

Mention the similarity between autogamy and geitonogamy

Mention a product of human welfare obtained with the help of the following microbes:
Aspergillus niger.