Question

Most mutations that affect the function of genes are categorized as loss-of-function mutations. Why?

A) the only way a mutation can change a gene is to decrease its function
B) DNA sequence changes that increase gene function are not considered mutations
C) gain-of-function mutations are always eliminated by natural selection
D) a random DNA sequence change is more likely to disrupt or decrease the function of a gene than to increase its function or add a new function
E) both A and B are true

Answer 1

Most mutations are categorized as loss-of-function because a random change in a gene's DNA is more likely to disrupt its function than enhance it, akin to a random change in a complex machine.

Step-by-step explanation:

The reason most mutations that affect the function of genes are categorized as loss-of-function mutations is because a random DNA sequence change is more likely to disrupt or decrease the function of a gene than to increase its function or add a new function. It's similar to making a random change in a complicated machine like a car engine; it's far more likely to result in decreased performance than an improvement. Therefore, the correct answer to the question is D) a random DNA sequence change is more likely to disrupt or decrease the function of a gene than to increase its function or add a new function.