A frameshift mutation could result from

A frameshift mutation could result from 

A) a base insertion only.
B) a base deletion only.
C) a base substitution only.
D) deletion of three consecutive bases.
E) either an insertion or a deletion of a base.






Answer: E

What is the effect of a nonsense mutation in a gene?

What is the effect of a nonsense mutation in a gene? 

A) It changes an amino acid in the encoded protein.
B) It has no effect on the amino acid sequence of the encoded protein.
C) It introduces a premature stop codon into the mRNA.
D) It alters the reading frame of the mRNA.
E) It prevents introns from being excised.





Answer: C

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product? 

A) a deletion of a codon
B) a deletion of two nucleotides
C) a substitution of the third nucleotide in an ACC codon
D) a substitution of the first nucleotide of a GGG codon
E) an insertion of a codon






Answer: B

In the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals–she used nitrogen mustards–have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?

In the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals–she used nitrogen mustards–have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation? 

A) We worry that it might cause mutation in cereal grain plants.
B) We want to make sure that it does not emit radiation.
C) We want to be sure that it increases the rate of mutation sufficiently.
D) We want to prevent any increase in mutation frequency.
E) We worry about its ability to cause infection.






Answer: D