What is the consequence of mutation 1 on the polypeptide? i.e. How would you refer to this mutation?

Question

What is the consequence of mutation 1 on the polypeptide? i.e. How would you refer to this mutation?

BlackTom AI · Accepted Answer

A silent mutation alters a codon without changing the encoded amino acid because of the redundancy (degeneracy) of the genetic code. This is the key concept: multiple codons can specify the same amino acid, especially changes in the third (wobble) position.

1) Relevant concepts
- Genetic code degeneracy: several different nucleotide triplets (codons) can code for the same amino acid (e.g., GAA and GAG both code for glutamic acid; GCU/GCC/GCA/GCG code for alanine).
- Types of point mutations: silent (no amino acid change), missense (different amino acid), nonsense (introduces stop codon), frameshift (insertion/deletion shifting reading frame).

2) Step-by-step reasoning
- Observe that mutation 1 changes one nucleotide in a codon but does not alter the amino acid incorporated into the polypeptide.
- Because the codon still corresponds to the same amino acid, the primary sequence of the polypeptide is unchanged.
- Therefore the mutation does not affect the polypeptide sequence and is classified based on effect on translation: silent.

3) Intermediate demonstration (example)
- Example substitution: GAA → GAG (both code for glutamic acid). A single-base change yields the same amino acid, so the polypeptide remains identical.

4) Why the correct answer is correct
- A silent mutation, by definition, results in no change to the polypeptide sequence despite a nucleotide change. Mutation 1 fits this definition because the codon change does not alter which amino acid is specified.

5) Why the other options are incorrect
- Missense: would change the amino acid; not the case here.
- Nonsense: would convert a codon into a stop codon, truncating the polypeptide; not observed.
- Frameshift: requires insertion/deletion not in multiples of three, altering downstream reading frame; mutation 1 is a single-base substitution, not an indel.

Conclusion: Mutation 1 is a silent mutation, matching the provided answer "Silent."

What is the consequence of mutation 1 on the polypeptide? i.e. How would you refer to this mutation?单项选择题

类似问题

What is the consequence of mutation 2 on the polypeptide? i.e. How would you refer to this mutation?

If the two blue bases were deleted, predict what would happen to the protein sequence and determine if the protein would still be active. One sentence only.

If the bolded bases (AAA) were deleted, predict what would happen to the protein sequence and determine if the protein would still be active. One sentence only.

Match each term regarding mutation on the left with the item that is most associated with it on the right. 1: suppressor mutation 2: transition 3: transversion 4: trinucleotide repeat 5: ultraviolet light

In the "Seeds of Dissension" case study, the DNA sequence analysis demonstrated that the SeedGene and ExOil seeds

Scientists were examining the maize genome. They noticed the genome had changed over time. What was likely the cause of the changes to the genome?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单