Question

The phenomenon of Coupling and repulsion was explained by
A. Bateson and Punnett
B. Beadle and Tatum
C. Bridges
D. Morgan

Answer 1

Hint: The scientist who has given the coupling and repulsion approach worked on the sweet pea or Lathyrus odoratus. It was found that the gene pairs do not assort independently.

Complete step-by-step answer:
In the coupling and repulsion theory it was found that genes for flower colour and pollen shape are well organized and they do not assort independently like the Mendel’s law of independent assortment. The test cross in independent assortment should be 1:1:1:1 but in this case it was found 7:1:1:7. Coupling is the mechanism when the genes coming from similar parents start entering the same gametes and are together inherited whereas in the repulsion mechanism the genes are inherited separately coming from the contrasting parents and they go into distant gametes. The experiment conducted by Bateson and Punnett lacks independent assortment. Morgan with different scientists explained the Chromosomal theory of linkage in the species Drosophila.
The main points of chromosomal theory of linkage are: a) Linked genes are positioned on the corresponding chromosome. b) Linked genes are inherited in sync. c) Linear arrangement of genes is found in the chromosome. d) The genes which are intimately related have the linkage strong whereas the genes which are in the far show weak linkage by this manner the strength of linkage can be explained. e) Morgan explained that Coupling and repulsion are the two outlooks of linkage.

Therefore the correct answer is A. Bateson and Punnett.

Note: Linkage is the method where the genes are inherited in sync on a single chromosome. Linked genes are grouped as complete linkage as well as incomplete linkage. Complete linkages are firmly positioned on the similar chromosome whereas incomplete linkages are located far on chromosomes with non -parental combinations.