Question

Differentiate between the one gene-one enzyme hypothesis and the one gene-one polypeptide hypothesis.

Answer 1

Feature	One Gene-One Enzyme Hypothesis	One Gene-One Polypeptide Hypothesis
Proposed By	Beadle and Tatum (1941).	Developed as an improvement over the original hypothesis.
Main Concept	Each gene is responsible for the production of a single specific enzyme.	Each gene is responsible for the synthesis of a single polypeptide chain.
Scope	Assumed all gene products are enzymes.	Recognises that genes also code for non-enzymatic proteins (like collagen or haemoglobin).
Biological Fact	Many proteins consist of multiple different polypeptide chains (e.g., Haemoglobin has alpha and beta chains), each coded by a different gene.	Acknowledges that a single enzyme might be made of multiple polypeptides from different genes.
Limitation	It failed to explain proteins that are not enzymes or enzymes made of multiple subunits.	It is more accurate but still limited (doesn’t account for alternative splicing, where one gene can make multiple proteins).