Question 1

Which of the following best describes the percentage of DNA sequence that is identical among all humans?

Accepted Answer

Approximately 99.6% of DNA bases are identical in all humans.

Question 2

A single nucleotide polymorphism (SNP) is best defined as:

Accepted Answer

A variation at a single base pair in the DNA sequence among individuals.

Question 3

Which of the following is NOT a likely consequence of a missense mutation?

Accepted Answer

No change in the amino acid sequence of the protein.

Question 4

A frameshift mutation is most likely caused by:

Accepted Answer

An insertion or deletion of nucleotides not in multiples of three.

Question 5

Which of the following best explains why people have different skin colors?

Accepted Answer

Variation in the amount and types of melanin produced by melanocytes, controlled by multiple genes.

Question 6

Which type of genetic variation is most likely to result in a change in the number of copies of a particular gene?

Accepted Answer

Copy Number Variant (CNV)

Question 7

A nonsense mutation in a gene is most likely to result in:

Accepted Answer

A premature stop codon, leading to a truncated protein.

Question 8

Which of the following best describes the concept of genetic variation?

Accepted Answer

Differences in sequences of genes between individual organisms of a species.

Question 9

A patient is found to have a mutation that removes an intron from a gene that normally includes it. This is most likely an example of:

Accepted Answer

A splice site mutation.

Question 10

Which of the following is a real-world example of a disease caused by a single nucleotide substitution?

Accepted Answer

Sickle cell disease

Question 11

If a mutation occurs during DNA replication and is not repaired, what is the most likely outcome?

Accepted Answer

The mutation will be passed on to daughter cells.

Question 12

Which of the following best describes a polymorphism?

Accepted Answer

A genetic variant that is common in the population (typically \u003e1% frequency).

Question 13

Which of the following equations best represents the calculation of the percentage of identical DNA bases between two humans, given 0.4% variation?

Accepted Answer

$$100\% - 0.4\% = 99.6\%$$

Question 14

Which of the following is NOT a type of mutation that can affect protein coding genes?

Accepted Answer

A change in the number of mitochondria in a cell.

Question 15

A person with a genetic variant that causes lactose intolerance is most likely to:

Accepted Answer

Have a reduced ability to digest lactose due to a variant in the lactase gene.

Question 16

Which of the following best explains why genetic variation is important in medicine?

Accepted Answer

It helps explain differences in disease risk, drug response, and quantitative traits among individuals.

Question 17

Which of the following is a correct statement about the relationship between genetic variation and race?

Accepted Answer

Over 99.6% of DNA is shared among all humans, supporting the concept of one human race.

Question 18

Which of the following is an example of phenotypic variability due to genetic variation?

Accepted Answer

Differences in height, skin color, and blood pressure among individuals.

Question 19

A silent mutation is best described as:

Accepted Answer

A change in the DNA sequence that does not alter the amino acid sequence of the protein.

Question 20

Which of the following is a likely effect of a copy number variant (CNV) in a gene involved in drug metabolism?

Accepted Answer

Altered response to medication due to increased or decreased gene dosage.

Human Genetic Diversity: Mutations & Polymorphisms

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