Question

Fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of chromosome theory of inheritance by Morgan and his colleagues because.
A. It reproduces parthenogenetically
B. Smaller female is easily distinguishable from a large male
C. A single mating produces two young flies
D. It completes the life cycle in about two weeks

Answer 1

Hint:The chromosomal theory of inheritance was proposed by Thomas Hunt Morgan who studied fruit flies and provided the first strong confirmation of the chromosomal theory. The life cycle of the fruit fly Drosophila melanogaster was about two weeks, that is the life cycle of fruit flies is very short. Due to the single mating of Drosophila melanogaster, large numbers of offspring are produced at a time. Also, it is easier to recognize female Drosophila melanogaster than males as they are larger in size when compared to the male fruit fly.

Complete answer:1. Fruit fly Drosophila melanogaster reproduce sexually by ejaculating fluid containing a cocktail of sperm and sex peptides that have a striking effect on female behavior. The females are able to produce 500 eggs and will hatch in 24-30 hours. So it is clear that fruit fly doesn’t reproduce parthenogenetically. Hence option A is wrong.
2. The female fruit flies are larger in size than male fruit flies and not vice versa. Hence option B is also wrong.
3. During single mating of fruit flies a large number of offsprings are produced. Hence option C is also wrong.
4. The fruit flies complete their life cycle within a small duration of time that is about two weeks
So the correct option is D.

Note: Drosophila melanogaster is an organism that belongs to species of fly (the taxonomic order Diptera) in the family Drosophilidae. Drosophila melanogaster is known generally as the common fruit fly or vinegar fly.