Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

On a visit to a Hill station, one of your friend suddenly became 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.

What characteristics make a community stable?

Name the stress hormone in plants. Describe its physiological effects.

"The codon is a triplet and is read in a contiguous manner without punctuations." Provide the genetic basis for the statement.

A red–eyed heterozygous female fruit fly is crossed with a red–eyed male. Work out all possible genotypes and phenotypes of the progeny. Comment on the pattern of inheritance of eye colour in fruit flies.

1. It is generally observed that the children who had suffered from chicken - pox in their childhood may not contract the same disease in their adulthood. Explain giving reasons the basis of such an immunity in an individual. Name this kind of immunity.
2. What are interferons? Mention their role.

Name the different types of pollution.

‘There is a hole in the ozone layer.’ What do you understand by this ?

State what is apomixis. Comment on its significance. How can it be commercially used?

Prior a sports event blood and urine samples of sportspersons are collected for drug tests.

1. Why is there a need to conduct such tests?
2. Name the drugs the authorities usually look for.
3. Write the generic names of two plants from which these drugs are obtained.