Final answer:
The Chromosomal Theory of Inheritance attributes chromosomes as carriers of genes and the basis for genetic heredity. Developed by Sutton and Boveri, this theory builds upon Mendelian genetics and has been further refined through the work of Thomas Hunt Morgan and Alfred Sturtevant.
Step-by-step explanation:
Chromosomal Theory of Inheritance
The Chromosomal Theory of Inheritance was developed by Walter Sutton and Theodor Boveri in the early 20th century. This theory posits that chromosomes, which are found in the nucleus of cells, are the bearers of genes and, therefore, the units of heredity. Boveri's observations concerning the necessity of chromosomes for proper embryonic development in sea urchins, along with Sutton's observations of chromosome separation during meiosis, underpin this theory. Further advances to the theory include the work of Thomas Hunt Morgan, who provided scientific demonstration through his research in 1915, and Alfred Sturtevant, who developed a method for calculating recombination frequency to understand the positions and distances of linked genes on a chromosome. In essence, this theory aligns with the observations of Mendelian genetics, articulating that the behaviour of chromosomes during cell division—specifically segregation and independent assortment—as described by Mendel's laws, are central to inheritance. However, exceptions in the form of gene linkage and recombination, which occasionally disrupt these predictable patterns, were accounted for in Sturtevant's further elaboration of the theory.