Question 1

Chromosome 7 may lose an end piece resulting in Williams syndrome. This is an example of a chromosomal

Accepted Answer

Williams syndrome is caused by a deletion of genetic material from a specific region of chromosome 7. This loss of genetic material is responsible for the characteristic features of this condition.

Question 2

A known abnormality in a gene's sequence that can be linked to a genetic disease is called a(n)

Accepted Answer

A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be associated with a particular gene or trait, including diseases. It is used to identify individuals or species and can be a variation in DNA that may or may not directly cause disease.

Question 3

Genetic counseling can help determine the risk of inheriting sickle cell disease in a family.

Accepted Answer

Genetic counseling provides information and support to families at risk of inherited conditions like sickle cell disease, helping them understand their risk of inheriting or passing on the disease.

Question 4

Which of the following is considered a mutagen? Check all that apply.

Accepted Answer

The answer of Which of the following is considered a...

Question 5

An extra three nucleotides inserted into a gene will cause a frameshift mutation.

Accepted Answer

Inserting three nucleotides into a gene adds one codon without altering the reading frame of the other codons, so it does not cause a frameshift mutation.

Question 6

To perform an in vivo gene therapy treatment, cells are removed from the patient's body, normal genes are added to them, and then the cells are returned to the patient's body.

Accepted Answer

In vivo gene therapy involves directly delivering the therapeutic genes into the patient's body, without removing cells from the body. The description given refers to ex vivo gene therapy.

Question 7

A missing piece of chromosome 5 may result in a child whose glottis and larynx do not develop properly, resulting in an abnormal cry. This is called

Accepted Answer

Cri du chat syndrome is characterized by a high-pitched, cat-like cry in infants, which is due to a deletion of a part of chromosome 5 that affects the development of the glottis and larynx.

Question 8

A karyotype shows chromosomes arranged by

Accepted Answer

Karyotypes are visual representations of an organism's chromosomes, arranged according to their banding pattern, size, and shape to facilitate the identification of chromosomal abnormalities.

Question 9

Which of the following syndromes is caused by a translocation?

Accepted Answer

The answer of Which of the following syndromes is caused...

Question 10

A child with bluish-purple skin is found to lack the enzyme diaphorase and is subsequently diagnosed with which genetic disorder?

Accepted Answer

Methemoglobinemia is the correct answer because the lack of the enzyme diaphorase leads to an inability to reduce methemoglobin back to hemoglobin, resulting in a higher level of methemoglobin which causes a bluish-purple skin coloration due to the decreased oxygen-carrying capacity of the blood.

Question 11

A translocation chromosomal mutation is the exchange of segments between two homologous chromosomes.

Accepted Answer

A translocation chromosomal mutation involves the exchange of segments between two non-homologous chromosomes, not homologous ones.

Question 12

Chromosomes for karyotyping are often obtained from a blood sample. Red blood cells, however, cannot be used for this purpose because

Accepted Answer

Red blood cells in humans do not contain nuclei, making them unsuitable for karyotyping, which requires analysis of chromosomes found within the nucleus.

Question 13

A chromosome normally has the following sequence of genes: f-g-h-i-j-k-l-m. Upon testing, an individual is found to have the following sequence: f-g-h-i-j-k-k-j-i-l-m. What kind(s) of chromosomal mutation(s) does this chromosome have? Check all that apply.

Accepted Answer

The answer of A chromosome normally has the following sequence...

Question 14

Alleles associated with known genetic disorders can be detected using DNA microarray analysis.

Accepted Answer

DNA microarray analysis allows for the examination of thousands of genes simultaneously to detect variations, including those alleles associated with known genetic disorders.

Question 15

Amniocentesis may be preferred over chorionic villus sampling (CVS) for karyotyping because

Accepted Answer

Amniocentesis is generally considered to have a slightly lower risk of miscarriage compared to chorionic villus sampling (CVS), making it a preferred choice for some patients when considering the risks associated with each procedure.

Question 16

Inversions are chromosomal mutations that

Accepted Answer

Inversions are a type of chromosomal mutation where a segment of a chromosome is reversed end to end. This process does not add or remove genetic material but rather rearranges it, maintaining the same amount of genetic material within the cell.

Question 17

A parent carries a deletion on one of the two homologouschromosomes. What is the probability of this individual's child carrying the same deletion?

Accepted Answer

The child inherits one of the two homologous chromosomes from each parent. If one parent has a deletion on one chromosome, there's a 50% chance the child will inherit that chromosome with the deletion.

Question 18

Testing for a protein may help reveal whether or not an individual has a genetic disorder.

Accepted Answer

Testing for specific proteins can indicate the presence of a genetic disorder because the production or absence of certain proteins is often directly linked to genetic mutations.

Question 19

Mutations within genes always result in nonfunctional proteins.

Accepted Answer

Mutations within genes can result in a variety of outcomes, including nonfunctional proteins, proteins with altered function, or no change in protein function at all, depending on the nature of the mutation.

Question 20

Chorionic villus sampling carries less risk of causing miscarriage than amniocentesis.

Accepted Answer

Chorionic villus sampling (CVS) generally carries a slightly higher risk of causing miscarriage compared to amniocentesis. CVS is usually performed earlier in pregnancy (between 10 and 13 weeks) and has a miscarriage risk of about 0.5% to 1%, whereas amniocentesis is typically done between 15 and 20 weeks and has a miscarriage risk of about 0.1% to 0.3%.

Quiz 13: Mutations and Genetic Testing