Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?

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

What is amniocentesis and why there is a statutory ban on it?

“India has greater ecosystem diversity than Norway.” Do you agree with the statement? Give reasons in support of your answer.

Explain the effect on the characteristics of a river when urban sewage is discharged into it.

Write the difference between genetic biodiversity and species biodiversity that exists at all the levels of biological organisation.

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

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

The membranous cover of the ovum at ovulation is ______.

Correct sequence in development is ______.

______ is a lytic enzyme released by the sperm.

How does human sperm locomote?

Cryptorchidism is a condition where ______.

Freshly released human egg has ______.

Which one of the following statements about human sperm is correct?

Human eggs are______.