Question

Substitution mutations are(1 point)
True False
Always harmful


Only harmful if a resuting amino acid of the codon is changed


Never harmful


Sometimes silent mutations and not expressed

Answer 1

Let's evaluate each statement about substitution mutations:

1. **Always harmful** – **False**: Not all substitution mutations are harmful; some may have no effect (silent mutations), while others may have beneficial effects.

2. **Only harmful if a resulting amino acid of the codon is changed** – **True**: This is generally accurate. If the substitution changes the amino acid, it may affect protein function, but if it does not (as in silent mutations), it may not be harmful.

3. **Never harmful** – **False**: Substitution mutations can indeed be harmful, especially if they lead to a change in protein function.

4. **Sometimes silent mutations and not expressed** – **True**: Some substitution mutations are silent, meaning they do not change the amino acid sequence of the protein and thus may not have any effect.

So, the correct evaluations are:

- **Always harmful**: False
- **Only harmful if a resulting amino acid of the codon is changed**: True
- **Never harmful**: False
- **Sometimes silent mutations and not expressed**: True