Use the Figure to Answer the Question

question 13

Multiple Choice

Use the figure to answer the question.

Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with which of the following nutrient(s) ?

• A) nutrient A only
• B) either nutrient B or C
• C) nutrient C only
• D) nutrients A and C

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Definitions:

Agonist

A chemical or drug that binds to receptors in the body and causes a physiological response similar to the natural substance.

Drug Molecule

A small chemical compound that has a therapeutic effect when administered to treat or prevent a disease.

Curare

A toxin derived from plants found in South America, used historically as a paralyzing agent on arrows for hunting.

Paralyzing Poison

A toxic substance that can cause immobilization by affecting the nervous system or muscular function.