Question

garrod hypothesized that inherited diseases such as alkaptonuria, the inability to metabolize the chemical alkapton, occur because ...

many metabolic enzymes use dna as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with dna.

metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.

certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors.

genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

Explanation:

Garrod's hypothesis about inherited diseases like alkaptonuria centered around the idea that genes are responsible for producing specific enzymes. Inherited diseases occur because affected individuals have genetic defects that lead to a lack of certain enzymes (which are needed for metabolic reactions like metabolizing alkapton). Let's analyze the options:

• The first option is incorrect because metabolic enzymes do not use DNA as a cofactor.
• The second option is incorrect as alkaptonuria is not due to vitamin cofactor requirements or nutritional deficiencies.
• The third option is incorrect because ribozymes and splicing factors are not related to Garrod's hypothesis about enzyme - gene relationships in inherited metabolic diseases.
• The fourth option (the last option in the list) correctly states Garrod's hypothesis: genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

Answer:

D. genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes. (Note: Assuming the last option is labeled D; adjust the label according to the actual numbering in the question if different)