Human Reproduction — BIOLOGY STD 12 Science — Question

A teacher wants his/her students to find the genotype of pea plants bearing purple coloured flowers in their school garden. Name and explain the cross that will make it possible.

How HIV multiplies in the host body?

Briefly explain IVF and ET What are the conditions in which these methods are advised?

Explain any three measures which will control vehicular air pollution in Indian cities.

Why is there a decline in the population of fish-eating birds when the water body is amidst agricultural fields?

DNA separated from one cell, when introduced into another cell is able to bestow some of the properties of former to the latter. What is this change called in technical terms? Describe the experimental evidences which led to the discovery of the above phenomenon.

Public all over India is very much concerned about the deteriorating air quality in large parts of North India. Alarmed by this situation the Resident's Welfare Association of your locality organised an awareness programme entitled "Bury not burn'. They invited you, being a biology student to participate.

1. How would you justify your arguments that promote burying and discourage burning? (Give two reasons).
2. With the help of flowcharts, one for each practice, depict the chain of events that follow.

What accounts for the greater ecological diversity of India?

Write the difference between Darwinism and De Vries theory about evolution of life on earth.

Identify by giving reasons, the salient features of genetic code by studying the following nucleotide sequence of mRNA strand and the polypeptide translated from it.
(AUG UUU UCU UUU UUU UCU UAG) (Met - Phe - Ser - Phe - Phe - Ser)