Why are many mutations considered neutral in their effects?

• A. Because all mutations increase the fitness of an organism
• B. Because mutations always result in the loss of gene function
• C. Because they occur in non-coding regions or do not alter the amino acid sequence of proteins
• D. Because mutations are always repaired by cellular mechanisms

Answer: (C)

Verified step by step guidance

1. Understand what a mutation is: a change in the DNA sequence that can affect gene function or regulation.
2. Recognize that not all mutations affect an organism's traits or fitness; some occur in regions of DNA that do not code for proteins (non-coding regions).
3. Learn about synonymous mutations, which are changes in the DNA sequence that do not alter the amino acid sequence of the resulting protein due to the redundancy of the genetic code.
4. Realize that mutations in non-coding regions or synonymous mutations often do not change the protein's structure or function, making their effects neutral.
5. Conclude that many mutations are considered neutral because they either occur in non-coding DNA or do not change the amino acid sequence, thus not affecting the organism's fitness.