Write the differences between homologous organs and analogous organs.
(ii) Write tlie dilferences between the sex chromosomes of man and sexchromosones of woman.
(iii) Sex of achildis determined by the latler. How?

Explanation

i)
ii) Sex chromosomes are denoted as X and Y. A male cell contains XY sex chromosomes while a female cell contains XX sex chromosomes. A gamete contains only 23 chromosomes (23n). A sperm contains either an X or Y chromosome, i.e. there will be two sets of sperms. One set of sperm consists of only X chromosomes, while another set consists of only Y chromosomes. An ovum always contains an X chromosome. Sex of the child depends on the kind of sperm that fuses with the ovum.
ii) a] If the sperm with an X chromosome fertilizes the ovum of the X chromosome, the zygote would have XX chromosomes, and the child will be a girl.
b] If the sperm with the Y chromosome fertilizes the ovum of the X chromosome, then the zygote would have XY chromosomes, and the child will be a boy.