Question

Drosophila melanogaster is considered a model organism for many heredity experiments, however, male flies do not undergo recombination. How is this an advantage to genetic experiments and how can it help determine if genes are linked or not.

Answer 1

ANS : Male Drosophila flies do not undergone recombination because before the meiosis process there is lack of required proteins ,so that no crossing occur in the male drosophila.

Drosophila melanogaster is an ideal organisms for the hereditary experiments because due to its short life span, laid large number of eggs and easy to culture in laboratory this organism has four pairs of chromosomes and the genes could be mapped easily to study the genetic transmission ,the Drosophila genome has been sequenced and about nearly 60% of diseases causing gene a in humans also present in Drosophila .The human genome in some extend resemble with the Drosophila genome ,scientists easily study the chromosomal rearrangements, deletions under the microscope.

Recombination and the frequency of recombination also related to distances between the genes on the chromosomes and its occur during the prophase of meiosis and forms different combination alleles in the gametes if crossing over occurred .If P generation AA BB x aa bb formed gametes AB and ab and after fertilization the F1 generation Aa Bb produces the gametes AB, ab these are the original combination of alleles like P generation and Aa and Ab aB new combinations of alleles.