Organisms and Populations — BIOLOGY STD 12 Science — Question

What is the function of Leydig cells?

During DNA synthesis in bacteria, which enzyme is required?

Name any two assisted reproductive technologies that help infertile couples to have children.

State True/ False with explanation.
Abortions could happen spontaneously too. (True/ False)

The present population growth rate in India is alarming. Suggest ways to check it.

In some children, ADA deficiency can be cured by:

1. Bone marrow transplantation.
2. Enzyme replacement therapy.
3. Both (a) and (b).
4. None of the above.

Write the similarity between the wing of a butterfly and the wing of a bat. What do you infer from the above with reference to evolution?

In the given population growth curve.

1. What is the status of food and space in the curves (a) and (b)?
2. In the absence of the predators, which curve (a) or (b) would appropriately depict the prey population?

In the following pedigree chart, state if the trait is autosomal dominant, autosomal recessive or sex linked. Give a reason for your answer.

Mark the odd one in the following group.
PCR, Widal, rDNA technology, ELISA.