Question

In what study of XX-XO type method was done initially?
A. Drosophila
B. Butterfly
C. Grasshopper
D. Squash-Bug

Answer 1

Hint:-While XX females and XY males are produced by both mammals and fruit flies, their chromosomes meet these ends using very different means. In mammals and in insects, the sex-determining processes are somewhat distinct.

Complete solution:
The most complex species of species on the planet are insects, so it is not that shocking that they show substantial variation in their sex determination mechanisms. However, the majority of insects have dimorphic sex chromosomes, like most other species, that can be cytologically separated.
The sex-determination system of X0 decides the offspring 's sex. There's only one sex chromosome in this scheme, referred to as X. Males have only one X chromosome (X0), although there are two (XX) for females. The zero represents the exclusion of a second X. Maternal gametes often carry an X chromosome, so the identity of the offspring of the animals depends on whether the male gamete has a sex chromosome. Normally, his sperm comprises only one X chromosome or no sex chromosome at all.
Most humans have two sex chromosomes (XX) and are hermaphroditic in a version of this system , producing both eggs and sperm with which they can fertilise themselves, whereas rare individuals are male and only have one sex chromosome (X0). Parthenogenesis may occur through various pathways to produce either male or female offspring with X0 sex-determination.
A single-chromosome (XX / XO) sex determination scheme is often used by some grasshoppers; XX represents the female, males here have only one sex chromosome, so they are assumed to be XO. Therefore, since they contain two distinct forms of gametes, males are the heterogametic sex.
Therefore the correct answer is option (C).

Note:- Animals with two separate sex chromosomes have hetero-gammatic sex and are hence capable of developing two forms of gametes. Conversely, only one form of gamete can be generated by members of the homogametic sex. Males usually have one X and one Y chromosome in humans (as well as in many other animals), while females have two X chromosomes. In butterflies and moths (order Lepidoptera), this system is reversed: females are the heterogametic sex, while males are homogametic.