Human Health and Disease — BIOLOGY STD 12 Science — Question

Explain the role of alkaline phosphatase in recombinant DNA technology. What is the source of this enzyme?

How did the process of RNA interference help to control the nematode from infecting roots of tobacco plants? Explain.

Mention the function of trophoblast in human embryo.

Poaching of tiger is a burning issue in today's world. What implication would this activity have on the functioning of the ecosystem of which the tigers are an integral part?

Which causative organisms are responsible for ringworm? List any two symptoms of the disease.

Anita was happy when she gave birth to her first child. Her in-laws were dissatisfied at her not giving birth to a male child and blamed Anita. Anita tried to convince her in-laws that she had no role in the child's gender. They understood the biological reason but were yet to be satisfied. Anita's husband took up the matter and convinced the parents.
i. What values did Anita's husband show in the above situation?
ii. What governs sex determination in humans? How is it different from birds?
iii. Why can't Anita be blamed for not giving birth to a male child?

What is DNA polymorphism? Why is it important to study it?

Suggest three features of plants that will prevent insect and pest infestation.

A large number of married couples the world over are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.
State any two reasons responsible for the cause of infertility.

How many primary follicles are left in each ovary at puberty?