What is the cell that receives a recombinant gene called?

According to the Hardy-Weinberg principle, the allele frequency of a population remains constant. How do you interpret the change of frequency of alleles in a population?

OR

Coelacanth was caught in South Africa. State the significance of discovery of Coelacanth in the evolutionary history of vertebrates.

State the functions of mast cells in allergy response.

OR

State the function of interferons.

Name a disorder a human suffers from as a result of monosomy of the sex chromosome. Give the karyotype and write the symptoms.

In the T.S. of a mature anther given below, identify ‘‘a’’ and ‘‘b’’ and mention their functions.

OR

What is cleistogamy? Write one advantage and one disadvantage of it, to the plant.