Enhancement of Food Production — BIOLOGY STD 12 Science — Question

Given reasons: 2, 4-D is used as herbicide.

Mention the pollinating agent of an inflorescence of small dull-coloured flowers with well exposed stamens and large feathery stigmas. Give any one characteristic of pollen grains produced by such flowers.

Give the graphical representation of Hardy-Weinberg’s principle in the form of Punnet square.

All reproductive tract infections (RTIs) are STDs but all STDs are not RTIs. Justify with example.

An alien piece of DNA needs to be integrated to a specific sequence of host DNA for its cloning. Is it true? if yes, explain. If this DNA is not picked up by host cells. Can you suggest a reason for it?

What is the number of chromosomes in the following cells of a human female?
Ootid.

Give reasons : Common cold is the most frequent ! infectious disease in humans.

List any four withdrawal symptoms, if the regular dose of drug is not provided to a drug addict.

For production of edible vaccines plants are used. Explain this any one example.

Draw a diagram showing a developing foetus within the uterus and label six parts in it.