Given the mRNA sequence GGU-GCU-CCU-AUU, what would happen if a nucleotide was added at the fourth position in the chain? A. chromosomal mutation B. frameshift mutation C. substitution mutation D. deletion mutation
Biology · Middle School · Tue Nov 03 2020
Answered on
The option B is correct answer.
If a nucleotide were added at the fourth position in the mRNA sequence GGU-GCU-CCU-AUU (assuming we're talking about the codons), it would cause a frameshift mutation.
The original sequence GGU-GCU-CCU-AUU is divided into codons, each consisting of three nucleotides. For instance:
- GGU (Glycine)
- GCU (Alanine)
- CCU (Proline)
- AUU (Isoleucine)
Inserting an additional nucleotide at the fourth position would shift the reading frame of the codons. This would disrupt the correct grouping of nucleotides into codons, altering the entire sequence of amino acids that would be translated from this mRNA sequence. Therefore, this scenario represents a frameshift mutation.