Describe the chromosomal theory of linkage.

Explanation

Chromosomal îheory of Linkage. It was put forward by Morgan and Castle (1911). which states that linked genes occur on the same chromosome in a linear sequence and maintain parental combination of genes except for occasional cross overs. The main features of theory are (i) Linked genes are genes which stay together during transmission from generation to generation. (ii) Linked genes occur on the same chromosome. (iii) Genes are arranged in a linear fashion over the chromosome. (iv) Each gene occupies a specific place over the chromosome. . (v) Genes tend to maintain original parental combination of alleles with the exception of ar occasional crossing over. (vi) Crossing over occurs due to the weakening of linkage between two genes. Strength of the linkage increases with the druze in the distance and decreases with the increase ir distance two genes