TLDR CH 22 DUFF
What is the correct order of events in the normal pathway by which growth factors stimulate cell division? Place the first event at the top.
1. growth factor binds to a specific receptor, an intracellular signaling pathway activates, an activated cytoplasmic protein triggers, and then genes coding for proteins that control cell division are activated
which factor is likely to contribute to a change in a haplotype between generations?
Crossing over between molecular markers that are spaced far apart on the chromosome
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 event activates progression through the cell cycle?
Phosphorylation of Rb protein so that it no longer binds to transcription factor E2F.
Identical twins share a genetic disease more often than fraternal twins.
True
True or false: 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
Cancer can result from inactivation of which type of gene?
Tumor-suppressor gene
A dominant genetic disorder can be caused by ______, a situation where one functional copy of an allele does not produce a normal phenotype. Multiple choice question.
haploinsufficiency
The phenomenon in which a person has only a single functional copy of a gene which is not enough to produce a normal phenotype is called .
haploinsufficiency
The linkage of alleles or molecular markers along a single chromosome is called a(n)
haplotype
An association between a disease-causing allele and nearby molecular markers can be established because ______.
haplotypes do not usually change from generation to generation
An association between a disease-causing allele and nearby molecular markers can be established because ______
haplotypes do not usually change from generation to generation.
A cancer cell is a cell that ______.
has accumulated genetic changes that allow it to grow uncontrollably
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
Which statement is true of X-linked dominant disorders such as Rett syndrome and Aicardi syndrome?
males die at an early stage of development
An oncogene is formed when a proto-oncogene gains a ______.
mutation that causes its expression to be abnormally active
Haplotypes are relatively stable from one generation to the next because ______.
mutation that would change the haplotype are rare and crossing over is unlikely to occur for molecular markers that are close to each other.
Chromosomal abnormalities related to genetic diseases can be detected by
producing a karyotype
Chromosomal abnormalities related to genetic diseases can be detected by ______.
producing a karyotype
A normal, nonmutated gene that has the potential to become an oncogene is called a(n) __ oncogene.
proto
A normal gene that when mutated becomes an oncogene is called a(n
proto-oncogene
A cancer-causing mutation in the ras gene leads to an altered Ras protein that ______
remains bound to GTP
To determine whether a specific SNP can be associated with a disease, SNPs of a group of individuals without the disease are compared to another group of individuals ______.
who are all affected by the same disease
What is the inheritance pattern for a trait that is more likely to occur in females when it is lethal to males?
x-linked dominant
What is the inheritance pattern for a trait that more commonly affects males than females and can often be observed in brothers or fathers of a woman who has affected sons?
x-linked recessive
What is the inheritance pattern for a trait that more commonly affects males than females and which will occur in about 50% of the sons born to the unaffected daughter of an affected male?
x-linked recessive
Hemophilia A is a(n) ______ disorder caused by a defect in the ______.
x-linked recessive and clotting factor VIII
Colorblindness is an X-linked recessive trait. A phenotypically normal man and a colorblind woman have two sons. What is the probability that both of them are color blind? Assume no new mutations.
1/1
Consider the accompanying figure showing four variable sites along a chromosome that can have any of three different versions, A, B or C, at each site. Which combinations represent haplotypes for this individual?
1B 2B 3A 4B 1A 2A 3A 4A
Hemophilia is an X-linked recessive trait. A heterozygous female is married to a phenotypically normal male. What percentage of their offspring is expected to have hemophilia?
50% sons, 0% daughters
To stimulate the growth of epidermal cells, such as skin cells, which event would occur first?
An epidermal growth factor, EGF, binds to a receptor on the surface of a skin cell.
Suppose a disease-causing allele shows autosomal recessive inheritance. How could a carrier of this disease-causing allele be identified?
Carriers often show reduced activity for the enzyme encoded by the allele.
Which methods can be used at the DNA level to test for specific mutations related to a genetic disease?
DNA microarray analysis DNA sequencing Fluorescence in situ hybridization (FISH)
Ras protein is in its active form when it is bound to ______.
GTP
Which observations are consistent with a disease having a genetic basis?
Nephroblastoma is a cancer of the kidney that typically develops in children and is only rarely found in adults. Someone with a diagnosis of retinitis pigmentosa has learned that there are family members in the preceding three generations who had the disease. One family in the neighborhood has one parent and several children with severe hearing loss. No one in any of the other nearby families has deafness.
Cancer cells may carry gain-of-function mutations that increase the activity of an oncogene. In which of the following ways could the expression of the protein encoded by the oncogene be altered by this type of mutation?
The amount of protein produced from the oncogene is significantly increased. The structure of the protein is altered so that it is overly active. The protein is expressed in a cell type where it is not normally found.
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.
Consider the accompanying pedigree showing inheritance of hemophilia in the family of Queen Victoria and Prince Albert. If Xh is the allele for hemophilia and XH is the allele for normal blood clotting, what is the one possible genotype that is missing among the children of Beatrice and her husband, at the right of the figure?
XHXH
Suppose that a specific SNP has been associated with a certain disease as a result of a genome-wide association study. What are the possible effects of the SNP on gene expression?
a change in an enhancer, a change in the coding region of the gene and a change in the promoter region of the gene
A method for obtaining fetal cells in a sample of the fluid surrounding the fetus is called ______.
amniocentesis
The two common ways of obtaining cellular material from a fetus for genetic testing are__ and __ __sampling.
amniocentesis, chorionic villi or villus
Which of the following features are characteristic of autosomal recessive inheritance?
an affected offspring can have two unaffected parent, two affected individuals must have affected children the trait occurs in the same frequency in both males and females.
What is the inheritance pattern for a trait that occurs with equal frequency in both sexes and will be inherited, on average, by 50% of the offspring of an affected individual who had only one affected parent?
autosomal dominant
What is the inheritance pattern for a trait that occurs with the same frequency in both sexes and two affected heterozygous individuals have, on average, 25% unaffected offspring?
autosomal dominant
A malignant tumor
can form secondary tumors after spreading to other locations has cells with cancerous mutations leading to uncontrolled growth can invade nearby healthy tissue
in which disease do genetic changes lead to uncontrolled cell growth?
cancer
Chemicals in the environment that cause cancer are called
carcinogens
Most cancer cells are descendants of an original cell that acquired genetic changes. Therefore, cancerous growths are considered to be ______ in origin.
clonal
Hemophilia A, or classical hemophilia, is an X-linked recessive disorder caused by a defect in the gene that encodes the protein __VIII.
clotting factor
n a genome-wide association study, the group of individuals without the disease is called the___ group
control
Twins that share about 50% of their genetic material are called ______ twins.
dizygotic
SNPs that may be causally linked to the development of a specific disease may be due to changes in the coding sequence or promoter region of a gene or to a change in a regulatory sequence such as a(n
enhancer or silencer
A carcinogen is a(n)
environmental agent that causes cancer
Genetic disorders that are caused by defective enzymes are typically inherited in an autosomal dominant fashion.
false
True or false: A disease with a genetic origin in a mouse is unlikely to be an inherited disease in humans.
false
Match the life stage to the type of screening used to detect a genetic disease.
fetus= Amniocentesis Newborn=PKU Adult=carrier
A disease-causing allele originates in a single individual who lived many generations ago. This individual, from whom the allele spreads throughout portions of the population over time, is known as the ______.
founder
There are three common explanations for autosomal dominant disorders: 1. Haploinsufficiency; 2.__ -of-__ mutations; and 3. Dominant- mutations.
gain of function, dominant negative
Linkage disequilibrium is a(n)
higher level of association between a disease allele and a molecular marker than would be expected by chance
Tay-Sachs disease is inherited with an autosomal recessive allele that leads to a defect in the enzyme hexosaminidase A. When cells are collected from patients, cells with different genotypes exhibit different amounts of enzymatic activity. Rank the amount of enzymatic activity that would be detected in a biochemical assay on cells from patients of these genotypes, with the genotype producing the LEAST amount of enzymatic activity on top
homo recessive, hetero, homo dominant
A karyotype can be used to __
identify changes in chromosome number and/or structure associated with a disease condition
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 benign tumor is a(n)
localized growth with a precancerous genetic change
A situation where a disease may be caused by mutations in two or more different genes is called ______.
locus heterogeneity
When a new mutation establishes a disease-causing allele in a family member, the allele's location can be traced through ______.
markers in a haplotype that are located nearby
Cancer cells can migrate to other parts of the body and cause secondary tumors. This property is called
metastatic
Twins that are genetically identical to each other are called ______ twins.
monozygotic
If a disorder has a genetic component, a pair of monozygotic twins is ______ dizygotic twins. Multiple choice question.
more likely to exhibit the disorder than
Which of the following characteristics of inheritance for hemophilia can be observed in the accompanying pedigree for the family of Queen Victoria and Prince Albert?
mothers of affected males often have brothers with the disease and males are more likely to be affected than females.
A dominant genetic disorder can be caused by a ______ mutation, where the product of an altered gene has an abnormal function.
gain-of-function
An oncogene is typically formed by a _______ mutation in a normal gene called a(n) _______.
gain-of-function ; proto-oncogene
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
Monozygotic twins
share 100% of alleles
What is the most common mode of transmission for genetic disorders involving defective enzymes?
autosomal recessive inheritance
Achondroplasia is an autosomal dominant disorder caused by a mutation in the fibroblast growth factor receptor-3 gene. The mutant form of the receptor is overactive, and thus disrupts the normal signaling pathway and leads to severely shortened bones. This is an example of a(n) -of- mutation.
gain-of-function
The ERBB2 receptor normally plays a role in promoting cell division. Cells from many breast cancer patients show an increase in the number of ERBB2 receptors available on the plasma membrane. The type of mutation that contributed to cancer development in these cases would be called a ______-of-function mutation in a(n) ______
gain; oncogene
Amniocentesis is a procedure for ______.
obtaining fetal cells in a sample from the fluid surrounding the fetus
During the initial stage of cancer development, cells with a precancerous genetic change form a(n) ______.
benine
A tumor-suppressor gene codes for a protein that normally _____
prevents cancerous growth
Dizygotic twins ______.
share an average of 50% of the same alleles
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
Which type of mutation causes a dominant genetic disorder through the production of an altered protein that works against the action of the normal protein?
dominant-negative
An investigation of the possible association between one or more single-nucleotide polymorphisms and a disease is called a(n) ______ association study.
genome-wide association study
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 ______. Multiple choice question.
haploid genotype showing linkage of alleles or molecular markers along a single chromosome
The ability of cancer cells to migrate to other parts of the body where they can cause secondary tumors is referred to as ______.
metastasis
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
During the initial stage of cancer development, cells with a precancerous genetic change form a(n) ______.
oncogene
Cancerous growths are clonal in origin because cancer cells ______
originate from a single cell that has accumulated genetic changes during cell division
Which gene plays a significant role in detecting DNA damage in a cell?
p53
a growth factor is a
signaling molecule that can stimulate cells throughout the organism's body to divide
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
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
Which type of growth has cells that can invade other tissues and migrate to other areas of the body to form secondary tumors?
malignant growth
A mutation that alters the gene product in a way that acts antagonistically to the normal gene product is called a dominant- mutation.
negative
