Question

What are homogametes and heterogametes?

Answer 1

The gametes of an organism are the reproductive or the sex cells. They can be of two types- Homogametes or Heterogametes. The gametes which are similar to each other are called Homogametes. Heterogametes differ from each other in shape and size.

Complete answer:
Sexually reproducing organisms reproduce by the fusion or fertilization of haploid gametes. It results in the formation of diploid individuals. The gametes also called the sex cells or the reproductive cells, carry only half of the genetic information. They are formed by meiosis or reductional division. The genetic constitution of gametes varies among the male and female gametes. Based on their shape, size, structure, and morphology the gametes can be further divided into two categories- Homogametes and Heterogametes.

Homogametes	Heterogametes
These gametes are similar in appearance.	These gametes are dissimilar in appearance.
They are also called Isogametes.	They are also called Anisogametes.
They have the same morphology and behavior.	They have different morphology or behavior.
The two gametes are equal in size and dimension and thus cannot be distinguished.	The two gametes differ in shape and size and thus can be easily distinguished. The larger gamete is called the Macrogamete, and the smaller gamete is called the Microgamete. Generally, the female gametes are larger and non-motile. And the male gametes are smaller and motile.
There is no such naming of the male and female gametes here.	In animals, the female gamete is called the ova or egg, and the male gamete is called the sperm.In plants, the male gamete is called the pollen grain, and the female gamete is called the ovule.

Note: Human females can also be called Homogametic since, they have similar pair of sex chromosomes- XX. Male humans are heterogametic as they have a different pair of sex chromosomes - XY. In birds, the females are heterogametic (ZW), and males are homogametic(ZZ).