Question

Briefly mention the contribution of T.H. Morgan in genetics.

Answer 1

Hint: Thomas Hunt Morgan received Nobel Prize in 1933 for his discoveries which elucidated the role of chromosomes in heredity.

Complete answer:
- Thomas Hunt Morgan was an American evolutionary biologist, geneticist, embryologist, and an author who was awarded the Nobel Prize for his work. He was the author of 22 books and 370 scientific papers.
- He worked on Drosophila melanogaster and gave the chromosomal basis for inheritance. One day he observed a fruit fly in which Instead of the normally brilliant red eyes of wild-type Drosophila melanogaster, white eyes were present.
- Morgan was interested in knowing how the traits were inherited and distributed in developing organisms. He started wondering what caused this fly's eyes to deviate from the norm.
- He was already familiar with breeding of drosophila in his lab so it was not so challenging for him to observe the transmission of genetic traits through successive generations, he thought to do simple breeding analysis to find out more about white eyes.

On the basis of results of his experiments, he stated that-
- The appearance of white eyes in females shows that this trait is not lethal in females.
- All possible combinations of white eyes and sex are possible.
- The white-eye trait can be carried over to females when F1 females are crossed with white-eyed males.
- By this experiment he proved the chromosomal theory of heredity and the inheritance of a specific trait on a single chromosome.

Note: T.H. Morgan gave the chromosomal theory of heredity which was further studied by Sutton and Boveri. On the basis of Morgan’s work, they later proposed the chromosomal theory of inheritance.