Question

How does the deletion of a single base cause a frameshift mutation?

a) It shifts the reading frame and alters the entire protein sequence.
b) It has no impact on the protein sequence.
c) It results in a point mutation.
d) It causes the protein to become shorter.

Answer 1

The deletion of a single base in DNA causes a frameshift mutation by shifting the reading frame, which changes the entire sequence of amino acids in the resulting protein, potentially leading to a non-functional protein.

Step-by-step explanation:

The deletion of a single base causes a frameshift mutation because it shifts the reading frame of the genetic code. This alteration changes every subsequent codon and can introduce premature stop codons, thereby changing the entire protein sequence.

During transcription, bases in mRNA are read in triplets, known as codons, which correspond to specific amino acids. A deletion or insertion that is not a multiple of three will offset these triplets, leading to a completely different set of codons downstream from the mutation. Consequently, this frameshift mutation can significantly affect the structure and function of the resulting protein, often rendering it non-functional.