Compare the two DNA sequences and polypeptide chains they produce. What type of mutation has occurred to the bottom sequence?

A.
Substitution

B.
Insertion

C.
Deletion

D.
No mutation

1 answer

To compare the DNA sequences and analyze the resultant polypeptide chains for mutations, I would need specific examples of the DNA sequences you're referring to. However, I can guide you on how to identify mutations based on the sequences provided.

Here’s how to identify mutations:

  1. Substitution Mutation: This occurs when one base pair is replaced by another. If the DNA sequence has changed in only one location and this leads to a different amino acid in the polypeptide chain, it's a substitution.

  2. Insertion Mutation: This involves the addition of one or more nucleotide bases into the DNA sequence. This can cause a frameshift, changing the way the rest of the sequence is read and likely altering the entire polypeptide chain from that point onward.

  3. Deletion Mutation: This is characterized by the removal of one or more nucleotide bases from the DNA sequence, also potentially causing a frameshift.

  4. No Mutation: If the DNA sequences are identical or result in the same polypeptide chain, then there is no mutation.

Steps to Determine the Mutation Type:

  • Compare the two DNA sequences side by side to identify any discrepancies.
  • Check the corresponding amino acid sequences to see how they differ.
  • A single change in base pairs that matches a change in a single amino acid indicates a substitution mutation, while changes that shift the entire reading frame suggest insertion or deletion mutations.

If you provide the specific sequences, I can help you analyze them further!