Final answer:
Archibald Garrod noted that enzyme deficiencies are inherited, contributing to the one gene-one enzyme hypothesis, and sowing the seeds for the eventual understanding of the role of DNA in heredity.
Step-by-step explanation:
In 1902, Archibald Garrod linked inheritance to proteins when he noted that enzyme deficiencies are inherited. His observations contributed to the understanding of how genetic disorders could be linked to specific metabolic pathways and pointed to the biochemical nature of genes.
Garrod's findings were foundational in the shift towards realizing that genes encoded for enzymes, and ultimately proteins; which are necessary for various cellular functions and are responsible for many inherited conditions. This marked the beginning of the one gene-one enzyme hypothesis. Later, with further discoveries in molecular biology, it was understood that genes encode for polypeptides, leading to the updated one gene-one polypeptide hypothesis.
Before this revelation, the nature of the genetic material was unclear, with many scientists considering proteins as the more likely candidates due to their complexity and diversity. Subsequent research, including the experiments conducted by Hershey and Chase, as well as the work of Avery, McLeod, and McCarty, revealed that DNA, and not protein, is the genetic material responsible for heredity.