Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Draw a schematic diagram of L.S. of a typical flower.

Distinguish between the following:
Ectotherms and Endotherms

Distinguish between the roles of flocs and anaerobic sludge digesters in sewage treatments.

Name any five hybrid varieties of crop plants which have been developed in India.

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?

DNA is unzipped twice in a cell. Mention the two events and the enzymes responsible for it.

Study the figures given below and answer the question.

Identify in which of the crosses is the strength of linkage between the genes higher. Give reasons in support of your answer.

Three water samples namely river water, untreated sewage water and Secondary effluent discharged from Sewage treatment plant were subjected to BOD test. The samples were labelled in 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 20 mg/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?

Explain the four basic process to increase or decrease in population density in a habitat.

Explain the role of tapetum in the formation of pollen grain wall.