Final answer:
Lederberg and Tatum observed chromosomal gene transfer to understand the mechanisms of heredity and genetic linkage, contributing to the Chromosomal Theory of Inheritance.
Step-by-step explanation:
Lederberg and Tatum observed the transfer of chromosomal genes because they were studying bacterial conjugation, a process involving a direct transfer of genetic material through cell-to-cell contact.
These researchers were not specifically focused on the transfer of plasmid genes, but rather on demonstrating the transfer of genetic information that could recombine to produce new genetic traits in a bacterial population. This was significant in helping to establish the foundation for bacterial genetics and microbial conjugation studies.
Their work provided additional support for the Chromosomal Theory of Inheritance, which identified chromosomes as the genetic material responsible for Mendelian inheritance.
Scientists like Theodor Boveri and Walter Sutton contributed to this theory by observing chromosomes during meiotic division, while Thomas Hunt Morgan and his colleagues provided experimental evidence with their studies on Drosophila melanogaster.
Thus, the transfer of chromosomal genes was central to understanding the mechanisms underlying heredity and genetic linkage.