If the wild-type codon is ggu, how many single-base substitutions will result in an amino acid substitution? include any changes from an amino acid codon to a different amino acid codon and any changes from an amino acid codon to a stop codon)

Approximately six

Explanation:

The codon GGU

Single base substitution that will change this codon that codes for glycine to another amino acid includes: a single base substitution in the GGU codon such as GGU - AGU can occur. thus, approximately six single base substitution can take place to change this codon to code for another amino acid. A single base substitution cannot change the codon to a stop codon unless it happens twice or there is more than a single base substitution.