Question
(a) Write about the scientific name of Drosophila. (b) Explain monohybrid cross of Drosophila through a checker board.
Answer
(a) The scientific name of Drosophila is Drosophila melanogaster. It is a species of fruit fly that has been widely used in genetics research.
(b) Monohybrid cross of Drosophila can be explained using a checkerboard. Let’s consider the cross between a homozygous dominant (BB) and a homozygous recessive (bb) Drosophila. The genotype of F1 generation will be Bb (heterozygous). To determine the genotype and phenotype of F2 generation, we can use a checkerboard:
| B | b | |
|---|---|---|
| B | BB | Bb |
| b | Bb | bb |
From this checkerboard, we can see that there are 3 possible genotypes in the F2 generation, i.e. BB, Bb, and bb. The ratio of these genotypes will be 1:2:1, which is the same as the monohybrid ratio derived by Mendel. Similarly, we can determine the phenotypic ratio of the offspring by counting the number of dominant (B) and recessive (b) traits. In this case, the phenotypic ratio will also be 3:1, where 3 individuals will have the dominant trait and 1 individual will have the recessive trait.
