Question

Five Mark Questions :
(a) Explain the mechanism of sex determination in humans.
(b) Differentiate between male heterogamety and female heterogamety with the help of an example of each

Answer 1

• Finding the sex of an individual as it begins life is known as sex determination. X chromosome carry genes for sex. X chromosome carries female determining genes and Y chromosome has male determining genes. The number of X and Y chromosome determines the female or male sex of an individual. Autosomes carry genes for the somatic characters that do not have any relation with the sex. Human has XX-XY type of sex determination where there is male heterogamy. The male hs\as XY chromosome and the females have XX chromosomes.

• The female heterogamy is seen in the birds and other reptiles where the female is ZW and the male is ZZ.