Name: Sex Determination (Drosophila melanogaster)
Uploaded: 2019-07-19
Duration: 7 min 20 s
Description: Drosophila melanogaster or the common fruit fly has contributed a lot to genetics. One of them is its sex determination system with more than five types of s...

Question

Explain the mechanism of sex determination in grasshopper and in bird.

Accepted Answer

In grasshopper, females have 22 autosomes plus XX and males have 22 autosomes plus XO chromosomes. Females produce eggs with 11 autosomes and an X. On the other hand, males produce sperms of two types. One with 11 autosomes and X. The other with 11 autosomes with no X chromosome. By fertilization, the zygote produced will have 22 autosomes and XX which develops as a female insect and the other zygote with 22 autosomes and XO which is developed as male.

Sex determination in Birds have the ZZ-ZW mechanism:

In birds, butterflies, moths, fishes, reptiles the males have homomorphic sex chromosomes known as ZZ and therefore are homogametic. It produces all similar gametes containing the Z chromosome. On the other hand, females have heteromorphic sex chromosomes known as ZW and therefore, are heterogametic and produce two types of eggs, with Z and with W chromosomes.

The egg with the 'Z' chromosome when fertilized by sperm with the Z chromosome the zygote formed is with ZZ chromosomes and is developed into a male bird. When the egg with the 'W' chromosome is impregnated by sperm with the Z chromosome, the resultant zygote is with ZW chromosomes which are developed as a female bird.

Explain the mechanism of sex determination in grasshopper and in bird.

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