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

The graph given below shows the number of primordial follicles per ovary in women at different ages. Study the graph and answer the questions that follow.

1. What is the average age of the women at the onset of menopause?
2. At what age are maximum primordial follicles present in the ovary, according to the given graph?

Explain the phases in embryonic development from the morula stage till the establishment of pregnancy in a human female.

Mention the problems that are taken care of by reproduction and child health care programme.

A large number of married couples the world over are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.

1. Why in your opinion the female partner is often blamed for such situations in India? Mention any two values that you as a biology student can promote to check this social evil.
2. State any two reasons responsible for the cause of infertility.
3. Suggest a technique that can help the couple to have a child where the problem is with male partner.

An infertile couple is advised to adopt test-tube baby programme. Describe two principle procedures adopted for such technologies.

If implementation of better techniques and new strategies are required to provide more efficient care and assistance to people, then why is there a statutory ban on amniocentesis? Write the use of this technique and give reason to justify the ban.

Explain the process of replication of a retrovirus after it gains entry into the human body.

1. What precaution(s) would you recommend to a patient requiring repeated blood transfusion?
2. If the advise is not followed by the patient, there is an apprehension that the patient might contract a disease that would destroy the immune system of his/her body. Explain with the help of schematic diagram only how the immune system would get affected and destroyed.

Name the kind of diseases/disorders that are likely to occur in humans if
    (i) mutation in the gene that codes for an enzyme phenyl alanine hydrolase occurs,
    (ii) there is an extra copy of chromosome 21,
    (iii) the karyotype is XXY.

Mention any one symptom of the diseases/disorders named above.

Explain one application of the following:
Amniocentesis

Explain one application of the following:
ZIFT

Prepare a poster for the school program depicting the objectives of:
"Reproductive and Child Health Care Programme".

Name the kind of diseases/disorders and any two symptoms that are likely to occur in humans if Mutation in the gene that codes for an enzyme phenylalanine hydroxylase occurs.

Name the kind of diseases/disorders and any two symptoms that are likely to occur in humans if The karyotype is XXY

An infertile couple was advised to undergo In vitro fertilization by the doctor. Out of the options given below, select the correct stage for transfer to the fallopian tube for successful results.

Trace the events from copulation to zygote formation in a human female.

‘An HIV patient normally doesn't die of ‘AIDS’, but death is caused due to many other infections.’ Do you agree with the statement? Give explanatory reasons in support of your answer.

Given below are four aspects of Reproductive Health in Column A and their related information in Column B:

Select the correct match from the following options:

A pregnant human female was advised to undergo MTP. It was diagnosed that the fetus she was carrying had developed from a zygote having 45 chromosomes with only one X chromosome.

1. What is this condition called and how does it arise?
2. Why was she advised to undergo MTP?