Identify the incorrect pair related to sex determination in various organisms:

Drosophila = XX-XO type

The correct answer is Option (3) -Drosophila = XX-XO type

Sex determination is the method by which the sex of an individual is decided. The sex here means male denoted by XY and female by XX.
For some organisms, sex is determined by the temperature and environmental factors inside the egg. But in humans the sex is determined on the presence or absence of sex hormones. Humans contain 23 pairs or 46 numbers of chromosomes. One pair among these pairs of chromosomes is the sex chromosome. The two types of sex chromosomes are X and Y. A female contains a pair of XX chromosomes in their cell. Male contains XY that is one X chromosome and one Y chromosome in their cell.

Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X-chromosomes.

 In Drosophila the males have one X and one Y chromosome, whereas females have a pair of X-chromosomes besides autosomes.

To distinguish the sex determination mechanism in birds from the one described earlier, female birds have been designated with two different sex chromosomes known as Z and W chromosomes. In these organisms, females possess one Z chromosome and one W chromosome, while males have a pair of Z chromosomes in addition to the autosomes.