Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

In the area of plant breeding, it is important not only to preserve the seeds of the variety being cultivated, but also to preserve all its wild relatives. Explain with a suitable example.

Name the improved characteristics of wheat that helped India achieve green revolution.

Enumerate the methods available for breeding for disease-resistance in plants.

How do you consider tendrils of Cucurbita and thorns of Bougainvillea as homologous structure?

1. Name the source plant of heroin drug. How is it obtained from the plant?
2. Write the effects of heroin on the human body.

Mention different agents for pollination.###Give reason plants pollinated by wind and water produce enormous amount of pollen.

Why do some plants have both chasmogamous and cleistogamous flowers?

Why T- DNA gene is harmful? How can we get benefit from it?

Mention the kind of biodiversity represented by more than a 1000 varieties of mangoes in India. How is it possible?

How is DNA isolated in purified form from a bacterial cell?
OR
List the four steps to isolate DNA from a bacterium.