1. Base-pair substitutions involving the third base of a codon areunlikely to re
ID: 2767 • Letter: 1
Question
1. Base-pair substitutions involving the third base of a codon areunlikely to result in an error in the polypeptide. This is because a. base-pair substituions are restriced to introns, and theseregions are later deleted from the mRNA. b. a signal-recognition particle corrects coding errors beforethe mRNA reaches the ribosome. c. base-pair substitutions are corrected before transcriptionbegins d. transcribed errors attract snRNPs, which them stimulatesplicing and correction. e. most tRNAs bind tightly to a codon with only the firstbases of the anticodon.a. base-pair substituions are restriced to introns, and theseregions are later deleted from the mRNA. b. a signal-recognition particle corrects coding errors beforethe mRNA reaches the ribosome. c. base-pair substitutions are corrected before transcriptionbegins d. transcribed errors attract snRNPs, which them stimulatesplicing and correction. e. most tRNAs bind tightly to a codon with only the firstbases of the anticodon.
Explanation / Answer
The answer is E. This is the result of wobble base pairing.mutations are not restricted to certain regions. SRP doesnt correcterrors and sometimes errors are not fixed.