Science (English Medium) कक्षा १२ - CBSE Important Questions for Biology

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

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

List the different types of pollination depending upon the source of pollen gain.

Why angiosperm anthers are called dithecous?

Explain the different ways apomictic seeds can develop, Give an example of each.

Mention one advantage of apomictic seeds to farmers.

Draw a labelled mature stage of a dicotyledonous embryo.

Describe the structure of its microsporangium.

Explain the events upto double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
 

Why does endosperm development precede embryo development in angiosperm seeds?

One of the major approaches of crop improvement programme is Artificial Hybridisation. Explain the steps involved in making sure that only the desired pollen grain pollinate the stigma of a bisexual flower by a plant breeder. 

Women are often blamed for producing female children. Consequently, they are ill-treated and ostracized. How will you address this issue scientifically if you were to conduct an awareness programme to highlight the values involved?

Comment on the role of placenta as an endocrine gland.

Your school has been selected by the Department of Education to organize and host an interschool seminar on “Reproductive Health – Problems and Practices”. However, many parents are reluctant to permit their wards to attend it. Their argument is that the topic is “too embarrassing.” Put forth four arguments with appropriate reasons and explanation to justify the topic to be very essential and timely.

Name the group of genes that have been identified in normal cells that could lead to cancer. How do these genes cause cancer?

Reproductive and Child Healthcare (RCH) programmes are currently in operation. One of the major tasks of these programmes is to create awareness amongst people about the wide range of reproduction related aspects. As this is important and essential for building a reproductively healthy society.

1. “Providing sex education in schools in one of the ways to meet this goal.” Give four points in support of your opinion regarding this statement.
2. List any two ‘indicators’ that indicate a reproductively healthy society.

Indiscrimate diagnostic practices using X-rays etc., should be avoided. Give one reason.

Our government has intentionally imposed strict conditions for M.T.P. in our country. Justify giving a reason.

Write the complete name of the diagnostic test for AIDS.

Given below are Column A with a list of certain Assisted Reproductive Technologies (ART) and in Column B the procedures followed during ART:

Choose the option where ART correctly matches with the procedure.