Question 1

Which of the following best describes how new alleles are generated in a population?

Accepted Answer

Through the process of mutation, which alters existing alleles.

Question 2

During DNA replication, DNA polymerase sometimes adds the wrong base. What is the most likely consequence if this error escapes repair?

Accepted Answer

A mutation will occur, potentially creating a new allele.

Question 3

Which type of mutation is most likely to result in a frameshift and dramatically alter the resulting protein?

Accepted Answer

Insertion or deletion of nucleotides not in multiples of three.

Question 4

A DNA sequence is transcribed to mRNA as follows: $3'\mathrm{TACCTTCGTGCA}\ 5' \rightarrow 5'\mathrm{AUGGAAGCACGU}\ 3'$. What is the corresponding amino acid sequence?

Accepted Answer

Met — Glu — Ala — Arg

Question 5

A point mutation changes a codon from $\mathrm{GAA}$ (coding for Glu) to $\mathrm{GAG}$ (also coding for Glu). What type of mutation is this?

Accepted Answer

Silent mutation

Question 6

Which of the following mutations is most likely to result in a loss of protein function due to a premature stop codon?

Accepted Answer

Nonsense mutation

Question 7

A mutation in the splice site of a gene prevents the removal of an intron from mRNA. What is the most likely outcome?

Accepted Answer

An abnormal protein is produced due to incorrect mRNA processing.

Question 8

Which type of mutation created the HbS allele responsible for sickle cell disease?

Accepted Answer

Missense point mutation

Question 9

In regions where malaria is common, which genotype leaves the most offspring and why?

Accepted Answer

Heterozygous (HbA/HbS), because it confers resistance to malaria without causing sickle cell disease.

Question 10

What is a balanced polymorphism, as seen in sickle cell disease and malaria resistance?

Accepted Answer

When two alleles are maintained in a population because heterozygotes have a reproductive advantage.

Question 11

Which of the following best explains why most single nucleotide polymorphisms (SNPs) have no effect on health?

Accepted Answer

They often occur in non-coding regions or do not alter the amino acid sequence.

Question 12

A mutation changes the amino acid at position 49 in the TAS2R38 taste receptor from proline to alanine. What is the likely effect?

Accepted Answer

Individuals with alanine at position 49 do not taste bitter flavors well.

Question 13

Which equation best represents the change in allele frequency in a population over time due to evolution?

Accepted Answer

$\Delta p = p' - p$

Question 14

If a DNA polymerase lacks proofreading ability, what is the expected effect on mutation rate?

Accepted Answer

Mutation rate will increase significantly.

Question 15

Which type of mutation is most likely to cause the absence of fingerprints (adermatoglyphia)?

Accepted Answer

Splice-site mutation

Question 16

A frameshift mutation occurs in a gene. Which of the following is most likely to happen?

Accepted Answer

The reading frame of the mRNA is altered, resulting in a completely different amino acid sequence.

Question 17

Which of the following best describes a somatic mutation?

Accepted Answer

A mutation that occurs in non-reproductive cells and is not passed to offspring.

Question 18

Which genotype is most resistant to malaria and why?

Accepted Answer

HbA/HbS, because heterozygotes are less likely to develop severe malaria.

Question 19

Which of the following is a real-world example of evolution by natural selection?

Accepted Answer

The increase in frequency of the HbS allele in populations exposed to malaria.

Question 20

Which process is responsible for correcting most pre-mutations during DNA replication?

Accepted Answer

Proofreading and mismatch repair enzymes

Genetic Mutations: Origins, Types, and Biological Consequences

Study Guide - Practice Questions

Study Guide - Flashcards