The sex chromosomes in females are

Two different types of gametes in terms of the sex chromosomes, are produced by

What type of sex determination is observed in grass hopper ?

The male human is represented by sex chromo-somes

$(a)$ In humans, males are heterogametic and females 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.

How is sex determined in various organism ? Give historical background of sex determination.