(a) In humans, males are heterogametic and frmales are homogametic, Explain. Are there any examples where males are homogametic and females heterogametic?
(b) Also describe as to, who determines the sex of an unborn child? Mention whether temperature has a role in sex determination.

Explanation

(a) The homogametic and hetrogametic refers to the organism depending upon wheter all the gametes contain one type of sex chromosome (homo same or two different types of sex chromosomes (hetero different).
Humans show XX/XY type of sex determination, i.e., frmales contain 2 copies of X-chromosome and males contain 1 X and 1 Y-chromosomes (meiosis). Therefore, the sperms are different with respect to the composition of sex chromosome.
In case of humans, females are condidered to be homogametic ehile males are hetergametic. Yes, there are example where males are homogametic and frmelas are heterogametic. In some birds the mode of sex determination is dented by ZZ (males) and ZW (females). Certain mothers and butterflies also show homogametic males and hetrogametic females.
(b) As a rule the heterogametic organism determines the sex of the unbron child. In case of humans, since males are heterogametic it is the father and not the mother who decides the sex of the child. In some animals lik,e crocodiles, lower temperature favour hatching of female offsprings and higher temperatures lead to hatching of male off springs.