Quiz 10 Q's

Question 1

A mutation that changes the codon UAA to the codon UAG in a mammalian cell line is called a(n)

Answer 1

synonymous mutation

Question 2

A mutation changes a codon from AAA (encoding lysine) to AGA (encoding arginine) in yeast, but no mutant phenotype is detected when the mutant strain is plated and grown on minimal or complete medium. This type of mutation is called

Answer 2

missense

Question 3

A mutation does not affect the length of a gene but results in an abnormally short protein. The mutation is most likely of a type called

Answer 3

nonsense

Question 4

A small (one-base-pair) insertion in the middle of the coding region of a gene will cause a

Answer 4

frameshift mutation

Question 5

A point mutation in a gene’s promoter will most likely cause the production of

Answer 5

reduced amounts of mRNA and protein

Question 6

The rare enol form of thymine pairs with guanine. If a thymine enolization occurs during replication, what would be the mutational event?

Answer 6

TA to CG

Question 7

After mutagen treatment, a molecule of 2-aminopurine (an adenine analogue) incorporates into DNA. During replication, the 2-AP protonates. The mutational event caused by this will be

Answer 7

AT to GC

Question 8

During mutagenic treatment with nitrous acid, an adenine deaminates to form hypoxanthine, which bonds like guanine. The mutational event would be

Answer 8

AT to GC

Question 9

Which mutagen causes transitions (usually GC to AT) by adding an alkyl group to a base (usually G), thus altering its pairing properties?

Answer 9

ethylmethanesulfonate (EMS)

Question 10

Which mutagen causes AT-to-GC transitions by acting as a base analog for adenine? Hint: It is unstable and readily undergoes tautomeric shifts. Its imino form pairs with C rather than G.

Answer 10

2 aminopurine