Question

part a
which of the following is the best claim about the cause of adenosine deaminase (ada) deficiency?
a ada deficiency is caused by a mutation in the ada enzyme.
b ada deficiency is caused by a virus that affects the immune system.
c ada deficiency is caused by changes to immune cells as a person ages.
d ada deficiency is caused by a mutation in the ada gene that changes the protein.

part a
which evidence best supports the claim in part a?
a mutations in the ada enzyme can cause less of the enzyme to be produced.
b viruses stop production of the ada enzyme.

Explanation:

For Part A: ADA deficiency is a genetic disorder caused by a mutation in the ADA gene, which alters the ADA enzyme, making it non-functional. This rules out virus-related or age-related immune cell change causes.
For Part B: To support the claim that ADA deficiency comes from an ADA enzyme mutation, evidence linking the ADA gene mutation to reduced/non-functional ADA enzyme production directly validates the cause.

Answer:

Part A: D. ADA deficiency is caused by a mutation in the ADA gene that changes the protein.
Part B: A. Mutations in the ADA enzyme can cause less of the enzyme to be produced.