Inheritance and Variation — BIOLOGY STD 12 Science — Question

Name and explain the surgical method advised to human males and females as a means of birth control. Mention its one advantage and one disadvantage.

Which are the two types of goitre? What are their causes?

What is ecological succession? Where and why would the rate of succession be faster, in a newly created pond or a forest destroyed by a forest fire?

List all the wastes that you generate, at home, school or during your trips to other places, could you very easily reduce? Which would be difficult or rather impossible to reduce?

Sketch and label T. S. of angiospermic anther.

A team of students are preparing to participate in the interschool sports meet. During a practice session you find some vials with labels of certain cannabinoids.

1. Will you report to the authorities? Why?
2. Name a plant from which such chemicals are obtained.
3. Write the effect of these chemicals on human body.

1. Expand VNTR and describe its role in DNA fingerprinting.
2. List any two applications of DNA fingerprinting technique.

A farmer while working on his farm was bitten by a poisonous snake. The workers in the farm immediately rushed him to the nearby health centre. The doctor right away gave him an injection to save his life. What did the doctor inject and why? Explain.

Water is very essential for life. Write any three features each for plants and animals, which enable them to survive in water scarce environment.

How does the transmission of each of the following diseases take place?
(a) Amoebiasis:
(b) Malaria:
(c) Ascariasis:
(d) Pneumonia: