Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

When does DNA replicate in the cell cycle?

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

Name the two semi-dwarf varieties of wheat introduced into all wheat growing places of India.

Mention any two significant roles predation plays in nature.

Malaria, typhoid, pneumonia and amoebiasis are some of the human infectious diseases. Which ones of these are transmitted through mechanical carriers?

Which fungus is used in the treatment of plant diseases under biological control.

It is a common practice to undertake desilting of the overhead water tanks. What is the possible source of silt that gets deposited in the water tanks?

What causes the annual variation in the intensity and duration of temperature?

Name the category of disease in which ‘Rheumatoid arthritis' in human, put under.
OR
Name the category of the disease, rheumatoid arthritis.

Tell the main function of circular DNA found in bacterial cells.