Give reason
a. Drosophila is the ideal material for genetic study.
b. Haemophilia is more common in males.
c. Aneuploidy leads to variation.
d. Sex of the child is determined by father.

Explanation

a. It breeds very quickly, it has a short generation time, produces nu merous offspring, only 4 pairs of chromosomes, the chromosomes can be easily distinguished with the help of microscope.
b. It is a .X. linked disorder. Male possesses only one X chromosome. So it is more common in males.
c. Aneuploidy is a chromosomal mutation that causes variation in chro mosome number which in turn leads to variation.
d. Father is heterogametic and produces two types of sperms i.e., half with X and half with Y. chromosomes.