Question 1

Which type of point mutation results in a codon that codes for the same amino acid as the original codon, thus having no effect on the protein sequence?

Accepted Answer

Silent mutation

Question 2

A mutation changes the DNA template strand from 3'-CCG-5' to 3'-CCA-5'. What is the effect on the protein sequence?

Accepted Answer

A silent mutation occurs, and glycine is still inserted

Question 3

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that changes a codon but still codes for an amino acid, though not the original one

Question 4

A nonsense mutation is most likely to result in:

Accepted Answer

A truncated, nonfunctional protein

Question 5

If a base-pair insertion or deletion is NOT a multiple of three, what is the most likely outcome?

Accepted Answer

A frameshift mutation

Question 6

Which of the following is TRUE about frameshift mutations?

Accepted Answer

They can cause extensive missense and premature termination

Question 7

A mutation in a gamete that is passed to offspring and causes sickle-cell disease is an example of:

Accepted Answer

A missense mutation

Question 8

Which of the following is a physical mutagen?

Accepted Answer

X-rays

Question 9

What is the probability that a spontaneous mutation will occur and be passed on to the next generation of cells?

Accepted Answer

$$1 in$$ $$10^{10}$$

Question 10

Which of the following statements about mutagens is correct?

Accepted Answer

Most mutagens are carcinogenic

Question 11

A base-pair substitution changes a codon from GAG to GUG in the hemoglobin gene. According to the genetic code, what amino acid change occurs?

Accepted Answer

Glutamic acid to valine

Question 12

If a mutation changes the mRNA codon from UGG (glycine) to UGA, what type of mutation is this?

Accepted Answer

Nonsense mutation

Question 13

Which scenario would most likely result in a protein with little effect on function?

Accepted Answer

A missense mutation where the new amino acid has similar properties to the original

Question 14

A chemical mutagen that inserts itself into DNA and distorts the double helix is most likely to cause:

Accepted Answer

Frameshift mutation

Question 15

Which of the following best describes the effect of an insertion or deletion of three nucleotides?

Accepted Answer

Extra or missing amino acid, but no frameshift

Question 16

A patient is exposed to UV light, which causes a mutation in their skin cells. What type of mutation is most likely to occur?

Accepted Answer

Physical mutagen-induced mutation

Question 17

Which of the following is NOT a possible outcome of a base-pair substitution?

Accepted Answer

Frameshift mutation

Question 18

A frameshift mutation occurs near the end of a gene. What is the most likely effect?

Accepted Answer

The protein may retain some function if the frameshift is near the end

Question 19

Which of the following best explains why some substitutions have little effect on protein function?

Accepted Answer

The new amino acid has similar properties or is in a non-essential region

Question 20

Which of the following is most likely to be inherited by offspring?

Accepted Answer

A mutation in a gamete

Point Mutations and Their Effects on Protein Synthesis

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