Dear student ....Drosophila is extensively used for biochemical and genetic work . The reasons are (1) They are easy to keep and work with .They can be easily grown on a ripened banana....(2) Drosophila has a short life cycle and produces large number of offsprings. Therefore , it is easy to study various generations of it ....(3) Drosophila has a small genome size .It has manageable number of chromosomes i.e., only 4 pairs .so it is easy to study their genomes.......With Regards ...Mahima...(Askiitians Forum Expert )