Question

In the BLASTX search with your cDNA sequence, you should only get matches in the +1, +2, or +3 reading frames because:

a) These frames represent the most conserved regions
b) These frames ensure accurate translation
c) These frames are associated with non-coding regions
d) These frames are less prone to mutations

Answer 1

In a BLASTX search, you only match with the +1, +2, or +3 reading frames because these correspond to the actual protein-coding sequence of the gene, which ensures accurate translation. Other frames would disrupt the codon reading and result in faulty protein synthesis.

Step-by-step explanation:

In a BLASTX search involving a cDNA sequence, you should indeed only get matches in the +1, +2, or +3 reading frames because these are the frames that ensure accurate translation of the genetic code from nucleic acid sequence into protein sequence. These frames start at the initiation codon and are successively read in triplets from the 5' to 3' direction, corresponding to the actual codons used during the process of translation.

When a frameshift mutation introduces a set of three nucleotides (a codon), it is often less deleterious than the insertion or deletion of a single nucleotide because it doesn't disrupt the entire reading frame downstream of the mutation, which would result in a completely different and usually nonfunctional protein. This is in contrast to a single nucleotide change that could dramatically alter the protein being translated.