Ecosystems — BIOLOGY STD 12 Science — Question

‘Fertilisation is not an obligatory event for fruit production in certain plants’. Explain the statement.

Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.

Name and explain three adaptations of mangroves to the conditions prevailing in Sunderbans (West Bengal).

Use of tobacco in any form is harmful to health. Explain .

List three symptoms of high altitude sickness and state three adaptations to overcome it.

(i) Which is that specific geographical area where these organism are found?
(ii) Name and explain the phenomenon that resulted in the development of so many dive species in this region.
(iii) Explain by writing the reasons how it was possible for the placental Wolf and Tasmanian wolf to live together in the same environment?

While on a visit to a pond in the city-neighbourhood, the visitors were delighted to find large expanse of water covered with colourful algal mass.

1. As a student of biology, do you agree with their delight? Give reasons in support of your answer.
2. Explain the cause of such algal growth.

1. Mention the property that enables the explants to regenerate into a new plant.
2. A banana herb is virus-infected. Describe the method that will help in obtaining healthy banana plants from this diseased plant.

A schematic diagram of matured human insulin is given below:

How is the process of its formation naturally in the human body different from that of its formation by rDNA technology? Explain.

Name the process of the rupture of Graafian follicle and the subsequent release of the egg from the ovary.