Week 14 chapter 22
The accompanying pedigree shows the inheritance of Huntington disease with filled symbols and also indicates which combination of four possible forms (A, B C, D) of a molecular marker called G8 that the person has inherited. Consider the couple that is surrounded by the red circle. Of their possible children, what phenotype and marker combination is missing?
BB without Huntington disease
Clinical improvement in leukemia patients has been observed when providing drugs that inhibit the enzyme ______.
DNA methyltransferase
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)
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?
Fluorescence in situ hybridization (FISH), DNA microarray analysis, DNA sequencing
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
Mutations in the genes for enzymes that catalyze the additions or removals of ______, _______, or ________ groups on histones have been implicated in the development of cancer.
acetyl, methyl, phosphate
test for carrier status if one belongs to a family with a history of a specific disease
adult
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
A method for obtaining fetal cells in a sample of the fluid surrounding the fetus is called ______.
anniocentesis
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
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
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
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 sleep disorder called narcolepsy has been linked to an allele for a faulty neural receptor in dogs. Some humans also suffer from narcolepsy.
consistent with a disease having a genetic basis.
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
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
The tumor-suppressor gene p53 has a significant role in ______.
detecting DNA damage in a cell
a genetic disease is spread to individuals sharing similar environmental situations
false
Amniocentesis and karyotyping to detect chromosomal abnormalities
fetus
an examination of genetic variants among many different individuals to determine if any variant is associated with a disease is called a _______ _______ association study
genome wide
An examination of genetic variants among many different individuals to determine if any variant is associated with a disease is called a ______-_______ association study.
genome wide association study
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
The linkage of alleles or molecular markers along a single chromosome is called a(n)
h
a haplotype is a _____
haploid genotype showing linkage of alleles or molecular markers along a single chromosome
An individual who is heterozygous for a defect in a tumor-suppressor gene ______.
has inherited an increased susceptibility to develop cancer
A cancer cell is a cell that ______.
have accumulated genetic changes that allow it to grow uncontrollably
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
linkage disequilibrium is a _______
higher level of association between a disease allele and a molecular marker than would be expected by chance
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
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
a situation where a disease may be caused by mutations in two or more different genes is called
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
Mutations in the gene encoding DNA ________, an enzyme catalyzing changes that inactivate genes, have been associated with the development of acute myeloid leukemia.
methyltransferase
To potentially reverse the inactivation of tumor-suppressor genes, researchers are developing potential cancer treatments that involve inhibition of the enzyme DNA _______
methyltransferase
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
Genome maintenance includes cellular mechanisms that prevent which two processes?
mutation; division or survival of mutant cells
test for excess phenylalanine demonstrating phenylketonuria (PKU)
newborn baby
Amniocentesis is a procedure for ______.
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
oncogene
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 inactive early in life
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
The study of genetic variations that cause differing responses to drugs is called ______.
pharamacogenetics
If an increase in DNA methylation of a gene is associated with an increase in severity of a specific disease, these two variables show a(n) ______.
positive correlation
A tumor-suppressor gene codes for a protein that normally ______.
prevents cancerous growth
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
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 rb allele; separate mutation events are required to inactivate each of these alleles
The process of converting a normal cell into a malignant cancer cell is called ______.
transformation
Comparing someone with a genetic disease to another person in the general population, the person with the disease is more likely to have a family member with the same disease.
true
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 clinincal data to select an individualized treatment