Organisms and Populations — BIOLOGY STD 12 Science — Question

Mention and describe any three methods to overcome inbreading depression in animal husbandry.
OR
List any three outbreeding practices carried out to breed domestic animals. Explain the importance of each one listed.

What is the basic cause of pollution?

On a visit to a Hill station, one of your friend suddenly become unwell and felt uneasy.

1. List two symptoms you would look for to term it to be due to allergy.
2. Explain the response of the body to an allergen.
3. Name two drugs that can be recommended for immediate relief.

Give the effects of water pollution on human health.

Transgenic animals are the animals in which a foreign gene is expressed. Such animals can be used to study the fundamental biological process, phenomenon as well as for producing products useful for mankind. Give one example for each type.

During a medical investigation, an infant was found to possess an extra chromosome 21. Describe the symptoms the child is likely to develop later in the life.

One of the twins born to parents having normal colour vision was colour blind whereas the other twin had normal vision. Work out the cross. Give two reasons how it is possible.

How do mycorrhizal fungi help the plants harbouring them?

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.

Identify 'a', 'b', 'c', 'd', 'e' and 'f' in the table given below:

No.	Syndrome	Cause	Characteristics of affected individual	Sex Male/Female/Both
1	Down’s	Trisomy of 21	‘a’ (i) (ii)	'b'
2	‘c’	XXY	Overall masculine development	‘d’
3	Turner’s	45 with OX	‘e’ (i) (ii)	‘f’