Alteration of the sequence of bases in DNA can alter the structure of proteins：练习题

Which of the following describes a substitution mutation that would result in a silent mutation, where the primary structure of the protein remains unchanged?

A mutation occurs where a segment of DNA is removed from one chromosome and inserted into a non-homologous chromosome. This type of mutation is known as a:

A substitution mutation occurs in a gene, changing the triplet \(CTC\) to \(CTT\). Both triplets code for the amino acid Leucine. Which property of the genetic code explains why the protein structure remains unchanged?

A mutation involves the deletion of a single nucleotide near the beginning of a gene's coding sequence. What is the most likely effect on the resulting polypeptide?

A point mutation occurs in a gene where a single base deletion takes place early in the sequence of an exon.
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}Explain why this type of mutation usually has a more significant impact on the resulting protein structure than a base substitution mutation.

A nonsense mutation occurs in the middle of an exon, changing a codon that previously coded for an amino acid into a stop codon.
Explain the likely effect of this mutation on the final tertiary structure of the protein.

A frameshift mutation is caused by the insertion of a single base pair in the first exon of a gene.
Contrast the effect of this mutation on the primary structure of the resulting polypeptide compared to a substitution mutation that occurs at the same position.