Question

Differentiate between male and female heterogamety.

Answer 1

Hint: Sexual reproduction involves the formation of male and female gametes either by the same individual or by different individuals. Heterogamety refers to the sex of a species in which the sex chromosomes are not the same. Homogamety refers to the sex if the species in which the sex chromosomes are the same or the organisms or individuals producing only one kind of gametes.

Complete step-by-step answer:
Gametogenesis refers to the process of formation of male and female gametes. Gametes are haploid cells. In some algae, the two gametes are similar in appearance that they are not able to categorize them into male and female gametes. They are called homogametic or isogametes. However, in the majority of sexually reproducing organisms, the gametes are two morphologically distinct types. They are known as heterogametes. In such organisms, the male gamete is called Antherozoid or sperm and the female gametes are called egg or ovum. While Heterogamety means different sex gametes. It refers to the sex of the species in which sex chromosomes are not the same. The differences between male and female heterogamety are the following;

MALE HETEROGAMETY	FEMALE HETEROGAMETY
Male Heterogamety includes human males having XY sex chromosomes and males of some insects having XO sex chromosome.	Female Heterogamety includes the females of some species of birds, fishes, and insects. Platypus males are heterogametic while females are homogametic.
In Drosophila, males are heterogametic.	Among insects, Lepidopteran has heterogametic females.
Humans males are heterogametic (XY). So, Men determine the sex of the baby depending on whether the sperm is carrying X or Y chromosome.	Human females are homogametic (XO). Thus, female has no role in determining the sex of the baby.

Additional Information:
- Due to the fusion of male and female gametes sexual reproduction results in the formation of offspring that are not identical to their parents.
- A haploid parent produces gametes by mitotic division and a diploid parent produces gametes by meiosis.
- In majority of organisms male gamete is motile and the female gamete is stationary. Exceptions are a few fungi and algae in which both types of gametes are motile.
- There is a need for a medium through which the male gametes move.
- In several plants like algae bryophytes and pteridophytes water is the medium through which gamete transfer takes place.
- A large number of male gametes fail to reach the female gametes, to compensate this loss male gametes are produced several thousand times the number of female gametes produced.

Note:
- The most important event of sexual reproduction is the fusion of gametes. This process is known as syngamy and it results in the formation of zygote.
 -In most aquatic organisms syngamy occurs in the external medium i.e. outside the body of the organism. For example, in algae, fishes, amphibians, etc.
- In some organisms like honey bees and even in some lizards and some birds the female gametes undergo development to form new organisms without fertilization. This process is known as Parthenogenesis.