Exam 15: Gene Mutation and Molecular Medicine

A disease that manifests itself in symptoms of neurodegeneration is passed down from generation to generation in a manner consistent with an autosomal dominant mutation.The symptoms tend to get worse in subsequent generations, with individuals showing symptoms at progressively earlier ages than their afflicted parents.What is the most reasonable hypothesis consistent with all of these facts?

Suppose you run gel electrophoresis using the standard voltage, but the spaces between the polymers of the gel are smaller than usual because of an error in making the gel.The samples are commonly run, so you neglect to include a lane with standards that would indicate the sizes of the bands.What is the most likely result?

During replication a DNA polymerase slips backward then resumes replication.Which replication error is likely to occur as a result?

The products of tumor suppressor genes _______ cell division; the products of oncogenes _______ cell division.

A couple hopes to be parents but are concerned that their child could end up with cystic fibrosis, as both of them have family histories of cystic fibrosis (CF).Neither exhibits symptoms of CF, but CF is a recessive disease, so they get the CF test done.This scenario presents an example of

Methylated _______ is particularly prone to mutation from deamination.

Suppose restriction enzyme A makes two cuts in a linear DNA fragment and restriction enzyme B makes one cut in that same DNA.The cuts are not in the same place, and no two of the cut fragments is exactly the same size.The digested samples are run in an electrophoresis gel.How many bands should the gel pick up if both enzymes A and B are used in the restriction digest?

If a mutation has a visible effect at 26°C, but no visible effect at 20°C, then 20°C is the _______ temperature and 26°C is the _______ temperature.

People are often more concerned about germ line mutations than somatic ones because germ line mutations

Refer to the table. A researcher is considering several new carrier viruses, listed in the table, to use in a gene therapy trial to treat Alzheimer's disease.Which type of virus would be the most successful for carrying the gene into the patients' brains?

A child born of parents heterozygous for sickle-cell disease is screened at birth for the disease and is diagnosed as heterozygous by allele-specific oligonucleotide screening based on the genotypes of the parents.Thus, it is an unpleasant surprise when the child exhibits the symptoms of a homozygous individual.The doctor concludes that the screening test failed to pick up the second abnormal HBB allele due to a _______ mutation.DNA sequencing later reveals a de novo loss-of-function mutation elsewhere in the HBB gene.

The standard test for PKU examines the _______ in the blood of newborns.

Refer to the figure. A child is born with a metabolic disorder in which there is a failure to produce an essential protein in brain development.This phenotype is the result of a single nonfunctional enzyme.The substrate for this enzyme does not build up in the brain, as it is essential for other metabolic pathways.Which is the best treatment strategy for this genetic disease?

The "P" in SNP stands for

Gain of function mutations

A woman whose mother has Huntington's disease is concerned that she may also have the disease, even though she is currently asymptomatic.She can get this information from

In allele-specific oligonucleotide hybridization for genetic screening, the probes are

A neonate is diagnosed with phenylketonuria (PKU).Is PKU an autosomal recessive or dominant disease? What is the genetic abnormality associated with this disorder?

DNA testing by allele-specific oligonucleotide hybridization

Certain kinds of breast cancer are treated with a drug that inhibits estrogen production in fatty tissue.What kind of therapeutic approach is this?