Coupling and repulsion hypothesis was given by

• A. Bateson and Morgan
• B. Morgan and Punnet
• C. Bateson and Punnett
• D. Morgan and Miller

The coupling and repulsion hypothesis is an important concept in genetics that deals with the behavior of linked genes during inheritance. This hypothesis was primarily formulated by A. Bateson and C. Punnett. Therefore, the correct answer to your question is C. Bateson and Punnett.

Understanding the Hypothesis

The coupling and repulsion hypothesis explains how alleles of different genes can be inherited together or separately. When two genes are located close to each other on the same chromosome, they tend to be inherited together, a phenomenon known as "coupling." Conversely, if the alleles are on different chromosomes or far apart on the same chromosome, they can assort independently, which is referred to as "repulsion."

Key Concepts

• Coupling: This occurs when two dominant or two recessive alleles are inherited together. For example, if we have two genes, A and B, and their dominant alleles are A and B, the coupling phase would involve the inheritance of AB together.
• Repulsion: This happens when one dominant and one recessive allele are inherited together. Using the same genes, the repulsion phase would involve the inheritance of Ab and aB, where A and b are inherited together, and a and B are inherited together.

Historical Context

A. Bateson and C. Punnett conducted experiments with sweet peas in the early 20th century, which led to the formulation of this hypothesis. Their work was pivotal in understanding how traits are passed from one generation to the next, especially in the context of linked genes.

Practical Implications

The coupling and repulsion hypothesis has significant implications in genetics, particularly in predicting the outcomes of genetic crosses. For instance, in a dihybrid cross, understanding whether genes are in coupling or repulsion can help predict the phenotypic ratios of the offspring. This is crucial for plant and animal breeding, as well as for studying genetic diseases in humans.

Conclusion

In summary, the coupling and repulsion hypothesis, proposed by Bateson and Punnett, provides a framework for understanding the inheritance patterns of linked genes. This concept not only enriches our knowledge of genetics but also has practical applications in various fields, including agriculture and medicine.