Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

What is it that prevents a child to suffer from a disease he/ she is vaccinated against? Give one reason.

Thymus of a new-born child was degenerating right from birth due to a genetic disorder. Predict its two impacts on the health of the child.

How many microspore mother cells would be required to produce one hundred pollen grains in a pollen sac? And why?

Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: GM foods are facing widespread resistance by the people.
Reason: GM foods have mutated genes which cause infections and allergies.

What is the basis of development of biodiversity hypothesis?

Name two microbes that are useful in biotechnology experiments.

What are seres?

Why have many animals not evolved thermo regulation?

Give an example of an organism that exhibits haplodiploid sex determination system.

(a) Write an example of a virus biocontrol agent.
(b) Why are they considered desirable for the treatment of an ecologically sensitive area?