Chapter 22 assignment

Which of the following accurately describes the genetic change(s) leading to malignancy?

A series of successive gene changes occurs, involving oncogene activation and inactivation of tumor-suppressor genes.

Which change from proto-oncogene to oncogene occurred by chromosomal translocation?

Creation of a new transcription factor through the fusion of chromosomal segments from two different chromosomes

Clinical improvement in leukemia patients has been observed when providing drugs that inhibit the enzyme ______.

DNA methyltransferase

A method that can identify genes that are active in cancer cells but inactive in normal cells is ______.

DNA microarray analysis

Which method can be used at the DNA level to detect the presence of a specific mutation in a disease-causing allele?

DNA microarray analysis

Which methods can be used at the DNA level to test for specific mutations related to a genetic disease?

DNA sequencing Fluorescence in situ hybridization (FISH) DNA microarray analysis

Genome maintenance includes cellular mechanisms that prevent which two processes?

Mutation; Division or survival of mutant cells

For the inherited tendency to develop retinoblastoma in the first few years of life, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model?

One allele is inactivated prior to birth, the other becomes inactivated early in life.

Which of these is a common example of widespread genetic screening of newborns to identify a specific disorder?

Test for excess phenylalanine indicating phenylketonuria (PKU)

For the non-inherited development of retinoblastoma, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model?

The person is born with two active copies of the rb allele; separate mutation events are required to inactivate each of these alleles.

Choose the observations that are consistent with a disease having a genetic basis.

The sleep disorder called narcolepsy has been linked to an allele for a faulty neural receptor in dogs. Some humans also suffer from narcolepsy. Tay-Sachs disease can occur in 1/2500 births in a specific eastern European population while the frequency is 1/250,000 across Europe. A cancerous growth of immature nerve cells called neuroblastoma is associated with a deletion in a specific region of chromosome 11.

The loss of a chromosome carrying a tumor-suppressor gene is an example of a way of losing the function of this gene through ______.

aneuploidy

What is the inheritance pattern when a trait occurs with the same frequency in both sexes and an affected offspring can have two unaffected parents?

autosomal recessive

What is the inheritance pattern when the trait occurs with the same frequency in both sexes and two unaffected heterozygotes have, on average, 25% affected children?

autosomal recessive

In which disease do genetic changes lead to uncontrolled cell growth?

cancer

Ewing's sarcoma is a cancer of the bone and soft tissues where a new transcription factor is produced from the fusion of the coding regions of two different proteins. The ews gene of chromosome 22 is joined to the fli1 gene of chromosome 11. Neither the ews nor the fli1 gene individually causes cancer. This change from proto-oncogene to oncogene occurred as a result of ______.

chromosomal translocation

DNA microarrays can be used to ______.

compare gene activity in cancer cells and normal cells

In cancer biology, transformation is the process of ______.

converting a normal cell into a malignant cell

If a comparison of two variables shows that they increase together, a positive ____________ is demonstrated and, if the results are statistically significant, a true ___________ between the variables is suggested.

correlation; association

The tumor-suppressor gene p53 has a significant role in ______.

detecting DNA damage in a cell

An investigation of the possible association between one or more single-nucleotide polymorphisms and a disease is called a(n) ______ association study.

genome-wide

A signaling molecule that can promote division of cells throughout the body of a multicellular organism is called a(n) ______.

growth factor

A haplotype is a ______.

haploid genotype showing linkage of alleles or molecular markers along a single chromosome

The linkage of alleles or molecular markers along a single chromosome is called a(n

haplotype

A cancer cell is a cell that ______.

has accumulated genetic changes that allow it to grow uncontrollably

An individual who is heterozygous for a defect in a tumor-suppressor gene ______.

has inherited an increased susceptibility to develop cancer

Most individuals who are born with an inherited form of cancer susceptibility are ______ for a defect in a ______.

heterozygous; tumor-suppressor gene

The development of cancer could be promoted if an abnormally ________ level of methylation occurred at CpG islands near the start site of a tumor-suppressor gene.

high

Which of the following is an epigenetic change that would likely lead to cancer?

hypermethylation inhibits the expression of a tumor suppressor gene

Molecular profiling is ______.

identification of the genes that play a role in the development of a specific type of cancer

Genetic testing is used to determine whether a(n) ______ has a disease-causing gene, while genetic screening is used to determine how frequently the gene is found in a(n) ______.

individual, population

If alleles and molecular markers are associated with each other at a frequency greater than expected by random chance, the situation is described as ______.

linkage disequilibrium

A situation where a disease may be caused by mutations in two or more different genes is called ______.

locus heterogeneity

The disease hemophilia is caused by a deficiency in any one of three blood clotting factors. Two of these factors are encoded by genes on the X chromosome and the other clotting factor gene is located on an autosome. Since mutations in more than one gene can cause hemophilia, this represents ______.

locus heterogeneity

Cellular mechanisms that prevent mutations from occurring and/or prevent mutant cells from dividing or surviving are referred to as genome ______.

maintenance

A series of genetic changes, involving oncogene activation and tumor-suppressor gene inactivation, leads to ______.

malignancy

To potentially reverse the inactivation of tumor-suppressor genes, researchers are developing potential cancer treatments that involve inhibition of the enzyme DNA

methyltransferase

The process of identifying the genes that play a role in the development of a specific type of cancer is called ______.

molecular profiling

Amniocentesis is a procedure forobtaining fetal cells in a sample from the fluid surrounding the fetus.

obtaining fetal cells in a sample from the fluid surrounding the fetus.

A gene that promotes cancer is called a(n) ______.

oncogene

A mutant gene that is overexpressed and contributes to the formation of cancer is termed a(n)

oncogene

Which gene plays a significant role in detecting DNA damage in a cell?

p53

Using information about a patient's genotype along with other clinical data to determine the best course of treatment is called ______.

personalized medicine

A tumor-suppressor gene codes for a protein that normally ______.

prevents for cancerous

A growth factor is a ______.

signaling molecule that can stimulate cells throughout the organism's body to divide.

Pharmacogenetics is the ______.

study of genetic variations that cause differing responses to drugs

To study the distribution of disease-causing genes, genetic ______ refers to determining if an individual carries the faulty gene, while genetic ______ relates to assessing the presence of the gene throughout a population.

testing; screening

Aneuploidy is a mechanism for losing the function of a tumor-suppressor protein because ______.

the chromosome carrying the tumor-suppressor gene can be lost from the cell

The process of converting a normal cell into a malignant cancer cell is called ______.

transformation

A gene that codes for a protein that prevents cancerous growth is a(n) ______.

tumor-suppressor gene

Personalized medicine is the ______.

use of information about a patient's genotype and other clinical data to select an individualized treatment