Human Reproduction — BIOLOGY STD 12 Science — Question

Explain into how many categories the endangered species have been classified on the basis of threatened species.

Differentiate between the following:Repetitive DNA and Satellite DNA.

How did the process of RNA interference help to control the nematode from infecting the roots of tobacco plants?
Or
How has RNAi technique helped to prevent the infestation of roots in tobacco plants by a nematode Meloidogyne incognita?

A person shows strong unusual hypersensitive reactions when exposed to certain substances present in the air, identify the condition. Name the cells responsible for such reactions. What precaution should be taken to avoid such reactions.

Explain three basic steps to be followed during genetic modification of an organism.

Differentiate the following and give examples:
Innate and acquired immunity.

Write any five common antibiotics with their sources.

Describe the development of endosperm after double fertilization in an angiosperm. Why does endosperm development precedes that of zygote?

1. Name the respective forms in which the malarial parasite gains entry into

1. Human body
2. Body of female Anopheles

2. Name the hosts where the sexual and the asexual reproductions of malarial parasite occur respectively.
3. Name the toxin responsible for the appearance of symptoms of malaria in humans. Why do these symptoms occur periodically?

A woman has certain queries as listed below, before starting with contraceptive pills. Answer them.
What schedule should be followed for taking these pills?