Coupling phase and repulsion phase terms were first described by which of the following?

✅Explanation:
The terms coupling phase and repulsion phase were first described by William Bateson and Reginald Punnett in 1906. They were studying the inheritance of flower color and pollen shape in sweet peas and observed that some genes seemed to be inherited together more often than expected by chance. They proposed that these genes were linked, meaning that they were located close together on the same chromosome.
-Coupling phase refers to the situation where the dominant alleles for two linked genes are on the same chromosome, and the recessive alleles are on the other chromosome. For example, if the dominant allele for flower color is red and the recessive allele is white, and the dominant allele for pollen shape is round and the recessive allele is long, then a plant in coupling phase would have the genotype RRL/rrl.
-Repulsion phase refers to the situation where the dominant allele for one linked gene is on the same chromosome as the recessive allele for the other linked gene. For example, a plant in repulsion phase would have the genotype RrL/rRl.

📌 Other options Explanation:
-B. Morgan: While Thomas Hunt Morgan was a contemporary of Bateson and Punnett and also worked on linkage
-C. Sturtevant: Alfred Sturtevant was a student of Morgan's and developed the first genetic map of a chromosome.

✏️D. Calvin Bridges: Calvin Bridges was another student of Morgan's who made significant contributions to the field of genetics.Related Terminology:
-Linkage: The tendency for genes located close together on the same chromosome to be inherited together.
-Recombination: The process of exchanging genetic material between different chromosomes.
-Genetic map: A diagram that shows the relative positions of genes on a chromosome.