Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Distinguish between
Production and decomposition.

When the relative frequency of the different phenotypes of a cross is plotted graphically, a bell-shaped curve results. Mention any four characteristics of such a pattern of inheritance.

A student on a school trip started sneezing and wheezing soon after reaching the hill station for no explained reasons. But, on return to the plains, the symptoms disappeared. What is such a response called? How does the body produce it?

Explain in brief:
(a) PCR, (b) Restriction enzymes and DNA, (c) Chitinase.

Following table gives certain terms associated with ART. Fill in the spaces a, b, c and d.

VF and ET	a
b	Introduction of zygote/ embryo with 8 blastomeres into fallopian tube.
c	Introduction of ova of a donor into the fallopian tube.
d	Introduction of semen from the husband or healthy donor into the uterus.

Find out the name of the microbes from which Cyclosporin A (an immunosuppressive drug) and Statins (blood cholesterol lowering agents) are obtained.

Differentiate between multiple allelism and pleiotropy with the help of an example of each.

How do 'implants' act as an effective method of contraception in human females? Mention its one advantage over contraceptive pills.

Name a disorder, give the karyotype and write the symptoms a human suffers from as a result of monosomy of the sex chromosome.

What are the major features of embryonic development at various months of pregnancy?