Organisms and Populations — BIOLOGY STD 12 Science — Question

Enzymes play an important role in detergents that we use for washing clothes. These enzymes are obtained from some unique microorganisms, enlist atleast two of them. Also name the enzyme.

Poaching of tiger is a burning issue in today's world. What implication would this activity have on the functioning of the ecosystem of which the tigers are an integral part?

Differentiate between wind pollinated and insect pollinated flowers.

Egrets are often seen along with grazing cattle. How do you refer to this interaction? Give reason.

Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

What do you understand by connecting Link? Explain their importance in biological evolution by giving suitable examples.

Name and explain the principle, the given equation represents: p² + 2pq + q² = 1.

A person has been diagnosed to be HIV positive.

1. Name the test which the person underwent.
2. Write the full name of the pathogen involved and describe its structure.
3. Which particular cells of this person are likely to get destroyed?

What is cleavage?

Embryo sacs of some apomictic species appear normal but contain diploid cells. Suggest a suitable explanation for the condition.