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

1 answer

Let's evaluate each statement about substitution mutations:

  1. Always harmfulFalse: 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 changedTrue: 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 harmfulFalse: Substitution mutations can indeed be harmful, especially if they lead to a change in protein function.

  4. Sometimes silent mutations and not expressedTrue: 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