Question

Cystic fibrosis is a disorder that causes the mucus glands to produce very thick mucus. Problems with the respiratory and digestive systems often occur in individuals with this condition. Like many disorders, cystic fibrosis occurs when there is a simple change, or mutation, in the DNA of a particular gene.

According to the information above, genetic mutations
A.
will always cause death in humans.
B.
can contribute to or cause diseases in humans.
C.
can only cause diseases in plants and wild animals.
D.
usually result in the release of excess mucus.

Answer 1

B. Genetic mutations can contribute to or cause diseases in humans.

Explanation: The passage states cystic fibrosis is caused by a mutation in a gene, showing that mutations can lead to human disease. The other choices are incorrect because mutations do not always cause death (A), are not limited to plants/animals (C), and do not usually produce excess mucus (D) — that is specific to certain conditions like cystic fibrosis.