Question

The fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of chromosomal theory of inheritance by Morgan and his colleagues because
A. It completes its life cycle in two weeks
B. It reproduces parthenogenetically
C. A single mating produces two young flies
D. None of the above

Answer 1

Hint: The studying of any kind of inheritance pattern is a long process and it may require that various generations of the subject organisms are needed to be studied in order to get the results. Also, the fruit flies are sexually dimorphic organisms.

Complete answer:
The group of scientists led by T.H. Morgan gave the theory of chromosomal inheritance. According to this theory the genes are located on the specific locations on the chromosomes. So, if we want to study the inheritance pattern, we need to study the pattern of phenotype for many generations in order to reach a conclusion. In order to achieve this, the organism which we are taking into consideration should be easily available, cheap, grow quickly, breeding is easier and one of the main point is that the life cycle of the organism should not be big so that the person have to wait for a long time to get the progeny.
So, from the given options, A might be correct because as shorter the life span as much earlier the conclusion will occur. Since having a life span of only two weeks it made it easier for Morgan to study the inheritance pattern in the flies easily over generations. Also, the fruit flies reproduce sexually by the formation of gametes and that is why the inheritance pattern can be studied. The inheritance pattern in pathogenetically reproducing organisms cannot be studied.
The fruit flies are known to lay numerous eggs as a result of the sexual reproduction and thus proving the option C wrong.

Therefore, from the discussion made above we can say that the option A is the correct answer.

Note:
The phenotype which was made the basis of the theory by Morgan was the colour of the eye of the fly. The dominant colour was the red colour. After the experiments it was found out that the gene regulating the colour of the eye was located on the X chromosome making it a sex linked character.