Human Reproduction — BIOLOGY STD 12 Science — Question

Ankit attended a blood donation camp to donate blood and came to know that he was HIV positive. He lost interest in studies knowing that. He remained absent from school for a long time. The biology teacher visited his house and talked to him. Ankit started coming to school again and showed interest in studies.

1. A person detected to be HIV positive should be isolated by the society. Do you agree? Why/ why not?
2. Write the processes through which, AIDS does not spread.
3. Who are at higher risk of encountering AIDS?
4. What sense of responsibility did the biology teacher exhibit?

Do you justify the statutory ban on aminocentesis in our country? Give reasons.

Why do you think the exine should be hard? What is the function of germ pore?

Draw a transverse sectional view of an apple and label the following parts along with their technical names:

1. Edible part.
2. Encloses the embryo.
3. Forms the fruit wall.

How tobacco plant is made pest resistance from nematodes?###Explain RNA interference with example.###Explain: Pest resistance Plants.

Different animals respond to changes in their surroundings in different ways. Taking one example each, explain "some animals undergo aestivation while some others hibernation". How do fungi respond to adverse climatic conditions?

Name the polymerase which is generally used in PCR? What is the source of this enzyme?

How does a restriction endonuclease help in DNA recombinant technology?

Give two examples of each:

1. Terrestrial ecosystem.
2. Aquatic ecosystem.
3. Man-made ecosystem.

'Sperm donation can help infertile couples'. Justify. In which type of cases, such sperm donation is helpful?