Question

ji wants to write an example of a frameshift mutation using the following sentence: the cat saw the rat. which sentence best shows a frameshift mutation?
○ thc ats awt her at.
○ cat the saw rat the.
○ eht tac was eht tar.
○ the the cat saw the rat.

Explanation:

A frameshift mutation occurs when nucleotides are inserted or deleted, shifting the reading frame of the genetic code, which disrupts the entire sequence of subsequent "words" (codons). Using the sentence analogy, this means adding or removing a single letter shifts how we split the sentence into 3-letter "words", making the rest unreadable.

• The first option removes the first 'E' from "THE", shifting the reading frame: splitting the new string into 3-letter chunks gives THC, ATS, AWT, HER, AT, which is a complete shift of the original "words".
• The second option rearranges existing words, which is like a chromosomal rearrangement, not a frameshift.
• The third option reverses each word, which is not a frameshift.
• The fourth option duplicates a word, which is like an insertion of an entire codon, not a frameshift that shifts the reading frame.

Answer:

A. THC ATS AWT HER AT.