Question

Who had proposed the chromosomal theory of the inheritance?

Answer 1

Chromosomal theory of inheritance states that chromosomes are the vehicles of genetic heredity. It was proposed by two scientists who had a German and an American origin.

Complete answer: Chromosomal theory of inheritance was given by Boveri and Sutton, but the confirmation of the chromosomal theory of inheritance was given by Thomas Hunt Morgan after studying the fruit flies. Chromosomal theory of inheritance was given independently by Walter Sutton after studying on grasshoppers and Theodor Boveri after studying on sea urchins.
Supporting observations for the chromosomal theory of inheritance are:
a. Chromosomes similar to genes or Mendelian factors occur in pairs. One feature of the pair is from the mother and the other is from the father.
b. This pair of homologous chromosomes separate at the time of gamete formation and one feature enters each gamete. This is similar to the conclusion stated by Mendel’s law of segregation.
c. One pair of chromosomes assort independently to the other pair of chromosomes similar to the allele of different genes assort independently according to Mendel Law of independent assortment

Additional information: Chromosomal theory of inheritance was confirmed by the study of T.H Morgan. He worked on fruit flies Drosophila melanogaster and found a mutation in gene causing eye colour in fruit fly which leads to white coloured eye instead of the red coloured eye. He came to know that the eye colour gene was inherited in the same pattern as the X chromosome and concluded that the gene for eye colour is present or is very tightly present on the X chromosome.

Note: Chromosomal theory of inheritance states genes as a unit of heredity and are located on chromosomes. T.H Morgan stated that if two genes are present on the same chromosome then the probability of parental combination is more than non-parental combination.