Genetics - Chapter 22

C) localized growth with a precancerous genetic change

A benign tumor is a(n) ______. A) invasive tumor that can grow within healthy tissues B) cancerous tumor that can spread to additional sites throughout the body C) localized growth with a precancerous genetic change

A) has accumulated genetic changes that allow it to grow uncontrollably

A cancer cell is a cell that ______. A) has accumulated genetic changes that allow it to grow uncontrollably B) no longer divides because most of its genes have been silenced C) divides more frequently than other cells, even though both types of cells have similar genetic compositions D) no longer divides because it receives fewer signals to initiate cell division

Oncogene

A mutant gene that is overexpressed and contributes to the formation of cancer

A) genome-wide

An investigation of the possible association between one or more single-nucleotide polymorphisms and a disease is called a(n) ______ association study. A) genome-wide B) population-wide C) sequence-specific D) inheritance E) disease

B) caspases

Apoptosis relies on the digestion of cellular proteins by enzymes called ______. A) dehydrogenases B) caspases C) lipases D) kinases E) nucleases

B) single-gene mutations at the DNA level

DNA microarrays can be used to detect ______ that are associated with a disease condition. A) changes in chromosome structure or number B) single-gene mutations at the DNA level C) differences in enzyme activity

D) benign growth

During the initial stage of cancer development, cells with a precancerous genetic change form a(n) ______. A) invasive growth B) malignant tumor C) metastatic tumor D) benign growth

E) 50% of the sons and 0% of the daughters

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? A) 100% of the sons and 0% of the daughters B) 50% of the sons and 50% of the daughters C) 100% of the sons and 50% of the daughters D) 50% of the sons and 100% of the daughters E) 50% of the sons and 0% of the daughters

A) more likely to exhibit the disorder than

If a disorder has a genetic component, a pair of monozygotic twins is ______ dizygotic twins. A) more likely to exhibit the disorder than B) less likely to exhibit the disorder than C) equally likely to exhibit the disorder as

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

Molecular profiling is ______. A) categorizing tumors based on their appearance under a microscope B) determining whether the genotype of the patient indicates high risk for cancer development C) identification of the genes that play a role in the development of a specific type of cancer D) developing a gene therapy method for treating a specific cancer patient

B) share 100% of their alleles

Monozygotic twins ______. A) share an average of 50% of their alleles B) share 100% of their alleles C) arose from two separate eggs, fertilized by separate sperm

Enhancer

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) __________________

C) proto-oncogenes; grow uncontrollably

Suppose a cell gains an extra copy of one chromosome. Overactive expression of ______ on that chromosome and its related homologues can cause the cell to ______. A) apoptosis-promoting genes; grow uncontrollably B) tumor-suppressor genes; grow uncontrollably C) proto-oncogenes; grow uncontrollably D) proto-oncogenes; stop dividing

a change in the promoter region of the gene a change in an enhancer a change in the coding region of the gene

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? Multiple select question. a change in the promoter region of the gene a change in an enhancer a translocation of the gene sequence to another chromosome an inversion of the region including the gene sequence a change in the coding region of the gene

A) heterozygous individuals show the tendency to develop breast cancer

The accompanying pedigree shows that breast cancer is inherited with a dominant allele showing incomplete penetrance. This is because ______. A) heterozygous individuals show the tendency to develop breast cancer B) all individuals inheriting at least one copy of the BRCA-1 allele develop breast cancer C) heterozygous individuals do not develop breast cancer

A) BB without Huntington disease

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 circle and enlarged in the inset. Of their possible children, what phenotype and marker combination is missing? A) BB without Huntington disease B) BB with Huntington disease C) CC with Huntington disease D) BC without Huntington disease

Apoptosis

The death of cells which occurs as a normal and controlled part of an organism's growth or development

D) detecting DNA damage in a cell

The tumor-suppressor gene p53 has a significant role in ______. A) promoting the formation of new alleles through mutation B) speeding up progress through the cell cycle C) preventing apoptosis D) detecting DNA damage in a cell E) preventing viral DNA insertion

B) monozygotic

Twins that are genetically identical to each other are called ______ twins. A) dizygotic B) monozygotic C) fraternal

D) X-linked dominant

What is the inheritance pattern for a trait that is more likely to occur in females when it is lethal to males? A) autosomal dominant B) X-linked recessive C) autosomal recessive D) X-linked dominant

B) 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? A) autosomal dominant B) X-linked recessive C) autosomal recessive D) X-linked dominant

C) autosomal dominant

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? A) X-linked dominant B) X-linked recessive C) autosomal dominant D) autosomal recessive

D) 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? A) autosomal recessive B) X-linked recessive C) X-linked dominant D) autosomal dominant

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

Which of the following accurately describes the genetic change(s) leading to malignancy? A) Multiple, simultaneous gene changes occur, involving oncogene activation and tumor-suppressor gene inactivation. B) A single genetic change occurs, involving inactivation of a tumor-suppressor gene. C) A series of successive gene changes occurs, involving oncogene activation and inactivation of tumor-suppressor genes. D) A single genetic change occurs, involving activation of an oncogene.

A) inactivated

A cancer-causing change occurs when a tumor-suppressor gene is ______. A) inactivated B) over expressed so that higher amounts of gene product are accumulated C) amplified so that the number of gene copies is increased D) moved to a new chromosomal location

C) remains bound to GTP

A cancer-causing mutation in the ras gene leads to an altered Ras protein that ______. A) does not participate in the pathway promoting cell division B) can no longer bind to GTP C) remains bound to GTP D) remains bound to GDP E) remains bound to ATP

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

A growth factor is a ______. A) signaling molecule that can stimulate cells throughout the organism's body to divide B) molecule that promotes programmed cell death through apoptosis C) molecule that can inhibit cell division D) protein on the surface of the cell that receives signals to increase the cell division rate

A) identify changes in chromosome number and/or structure associated with a disease condition

A karyotype can be used to ______. A) identify changes in chromosome number and/or structure associated with a disease condition B) detect a reduction in enzymatic activity due to a disease-causing allele C) determine the change in DNA sequence that converted a normal allele to a disease-causing allele

D) mutation that causes its expression to be abnormally active

An oncogene is formed when a proto-oncogene gains a ______. A) promoter mutation that prevents transcription of the coding region B) deletion that causes it to produce an inactive protein C) mutation that reduces its expression by 50% D) mutation that causes its expression to be abnormally active

D) gain-of-function; proto-oncogene

An oncogene is typically formed by a ______ mutation in a normal gene called a(n) ______. A) gain-of-function; tumor-suppressor gene B) loss-of-function; proto-oncogene C) loss-of-function; tumor-suppressor gene D) gain-of-function; proto-oncogene

A) recessive; must become homozygous for a loss-of-function allele

At the cellular level, breast cancer development is ______ because the cell ______. A) recessive; must become homozygous for a loss-of-function allele B) recessive; must become homozygous for a gain-of-function allele C) dominant; must become homozygous for a gain-of-function allele D) dominant; can be heterozygous for a loss-of-function allele

D) p21

By the action of tumor suppressor protein p53, which gene shows increased expression to slow progress through the cell cycle and provide time for DNA repair? A) e2f B) rb C) ras D) p21 E) myc

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.

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? Multiple select question The amount of protein produced from the oncogene is significantly increased. The structure of the protein is altered so that it is no longer active. The structure of the protein is altered so that it is overly active. The amount of protein produced from the oncogene is significantly decreased. The protein is expressed in a cell type where it is not normally found.

B) XHXH

Consider the accompanying partial pedigree showing the inheritance of hemophilia, focusing on one of Queen Victoria and Prince Albert's children named Beatrice. 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? A) XHXh B) XHXH C) XHY D) XhXh E) XhY

A) individual; population

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) ______. A) individual; population B) population; individual C) group of patients; individual

C) gene, its linkage to other genes or molecular markers

Haplotype association studies are aimed at the identification of a particular ____________ based on _____________ A) chromosome, an abnormality in its structure B) chromsome, the arrangement of molecular markers C) gene, its linkage to other genes or molecular markers D) gene, chromosomal rearrangements

mutations that would change the haplotypes are rare crossing over is unlikely to occur for molecular markers that are close to each other

Haplotypes are relatively stable from one generation to the next because ______. Multiple select question changes occur in haplotypes frequently for sites that are close together mutations that would change the haplotype are rare methylation of haplotype sequences causes crossing over crossing over is unlikely to occur for molecular markers that are close to each other

A) heterozygous for the autosomal dominant

In the accompanying pedigree, a filled symbol indicates an individual with Huntington disease while a clear symbol shows an unaffected individual. Considering the symbol for individual II-5, you conclude that her father, I-1 is ______ allele for Huntington disease. A) heterozygous for the autosomal dominant B) homozygous for the autosomal dominant C) heterozygous for the autosomal recessive D) hemizygous for the X-linked recessive E) hemizygous for the X-linked dominant

B) Carriers often show reduced activity for the enzyme encoded by the allele.

Suppose a disease-causing allele shows autosomal recessive inheritance. How could a carrier of this disease-causing allele be identified? A) Carriers show the same phenotype as individuals with the homozygous recessive genotype. B) Carriers often show reduced activity for the enzyme encoded by the allele. C) Carriers have a reduction in the amount of DNA present in the region containing the allele.

E) haplotype

This figure shows four variable sites along a chromosome that can have any of three different versions, A, B or C, at each site. For this individual, the listing 1C 2C 3C 4A is a ______. A) karyotype B) recombinant C) phenotype D) diplotype E) haplotype

B) testing; screening

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. A) diagnosis; screening B) testing; screening C) screening; testing D) analysis; testing

B) 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? A) X-linked recessive B) autosomal recessive C) autosomal dominant D) X-linked dominant

B) 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? A) autosomal dominant B) autosomal recessive C) X-linked recessive D) X-linked dominant

C) autosomal recessive inheritance

What is the most common mode of transmission for genetic disorders involving defective enzymes? A) X-linked dominant inheritance B) autosomal dominant inheritance C) autosomal recessive inheritance D) X-linked recessive inheritance

A) autosomal recessive

What is the most likely mode of inheritance of the trait exhibited in this pedigree? A) autosomal recessive B) X-linked recessive C) X-linked dominant D) autosomal dominant

Linkage Disequilibrium

When the disease-causing allele and nearby markers are associated more frequently than expected by chance

D) crossing over between molecular markers that are spaced far apart on the chromosome

Which factor is likely to contribute to a change in a haplotype between generations? A) crossing over between molecular markers that are spaced close to each other on the chromosome B) DNA methylation C) mutation D) crossing over between molecular markers that are spaced far apart on the chromosome

B) p53

Which gene acts to prevent the accumulation of mutations by activating DNA repair genes in cells with damaged DNA? A) ras B) p53 C) myc D) rb E) p21

D) p53

Which gene stimulates the expression of p21 to slow progress through the cell cycle when DNA damage is detected? A) ras B) myc C) rb D) p53 E) e2f

Mothers of affected males often have brothers with the disease. Males are more likely to be affected than females.

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? Multiple select question Mothers of affected males often have brothers with the disease. An affected individual must have an affected parent. Males and females are equally likely to have the disease. Males are more likely to be affected than females.

can invade nearby healthy tissue has cells with cancerous mutations leading to uncontrolled growth can form secondary tumors after spreading to other locations

A malignant tumor ______. Multiple select question can invade nearby healthy tissue remains at its original location has cells with cancerous mutations leading to uncontrolled growth has cells that acquired only precancerous mutations can form secondary tumors after spreading to other locations

D) malignancy

A series of genetic changes, involving oncogene activation and tumor-suppressor gene inactivation, leads to ______. A) formation of a benign growth B) apoptosis C) inhibition of the cell cycle D) malignancy

C) growth factor

A signaling molecule that can promote division of cells throughout the body of a multicellular organism is called a(n) ______. A) apoptosis factor B) tumor suppressor C) growth factor D) receptor E) enzyme

A) prevents cancerous growth

A tumor-suppressor gene codes for a protein that normally ______. A) prevents cancerous growth B) decreases the number of cancer-causing genes in the cell C) allows cells to move quickly through checkpoints in the cell division cycle D) stimulates the rate of cell division E) increases chromosomal rearrangements

D) dominant inheritance with incomplete penetrance

According to the accompanying pedigree, what is the inheritance pattern of the allele for inherited breast cancer, BRCA-1? A) recessive inheritance with complete penetrance B) dominant inheritance with complete penetrance C) recessive inheritance with incomplete penetrance D) dominant inheritance with incomplete penetrance

D) digest cellular proteins during apoptosis

Caspases are enzymes that ______. A) repair double-strand breaks in DNA B) activate transcription factors that stimulate cell division C) phosphorylate proteins involved in controlling the cell cycle D) digest cellular proteins during apoptosis

D) producing a karyotype

Chromosomal abnormalities related to genetic diseases can be detected by ______. A) assaying for enzyme activity B) DNA microarray analysis C) using a Western blot D) producing a karyotype

A) 100%

Colorblindness is an X-linked recessive trait. A phenotypically normal man and a colorblind woman have two sons. The probability that both of them are colorblind is ______. (Assume no new mutations.) A) 100% B) 50% C) 6.25% D) 25% E) 12.5%

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

For the inherited tendency to develop retinoblastoma in the first few years of life, which correctly describes inactivation of the rbtumor-suppressor alleles by the "two-hit" model? A) Both alleles are inactivated by environmental factors early in life. B) Both alleles are inactivated prior to birth. C) One allele is inactivated prior to birth, the other becomes inactivated early in life. D) Both alleles are eliminated by chromosomal deletions prior to birth.

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

For the non-inherited development of retinoblastoma, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model? A) The person is born with two inactive copies of the rb allele, followed by two more mutations in the allele causing further inactivation. B) The person is born with two inactive copies of the rb allele. C) The person is born with two active copies of the rb allele; separate mutation events are required to inactivate each of these alleles. D) The person is born with one inactive copy of the rb allele; a mutation inactivates the second rb allele.

D) X-linked recessive; clotting factor VIII

Hemophilia A is a(n) ______ disorder caused by a defect in the ______. A) X-linked dominant; beta-chain of hemoglobin B) X-linked dominant; clotting factor VIII C) X-linked recessive; beta-chain of hemoglobin D) X-linked recessive; clotting factor VIII E) autosomal recessive; clotting factor VIII

C) gain; oncogene

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) ______. A) gain; tumor-suppressor gene B) loss; oncogene C) gain; oncogene D) loss; tumor-suppressor gene

A) originate from a single cell that has accumulated genetic changes during cell division

Cancerous growths are clonal in origin because cancer cells ______. A) originate from a single cell that has accumulated genetic changes during cell division B) can form a tumor that is localized only at one site C) can migrate to other areas of the body and form secondary tumors at the new sites D) can invade healthy tissues

B) carcinogens

Chemicals in the environment that cause cancer are called ______. A) teratogens B) carcinogens C) toxic chemicals D) pollutants

1A 2A 3A 4A 1B 2B 3A 4B

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? Multiple select question 1A 2A 3A 4B 1A 2A 3A 4A 1B 2B 3B 4B 1B 2B 3A 4B 1A 2B 3B 4C

E) clonal

Most cancer cells are descendants of an original cell that acquired genetic changes. Therefore, cancerous growths are considered to be ______ in origin A) malignant B) invasive C) benign D) hereditary E) clonal

B) heterozygous; tumor-suppressor gene

Most individuals who are born with an inherited form of cancer susceptibility are ______ for a defect in a ______. A) heterozygous; proto-oncogene B) heterozygous; tumor-suppressor gene C) homozygous; tumor-suppressor gene D) homozygous; proto-oncogene

D) The sequence arrangement in the newly-fused chromosome leads to overactive expression of a proto-oncogene.

Suppose a translocation occurs so that a portion of one chromosome is joined to another non-homologous chromosome. Which situation would cause the cell to grow uncontrollably as a result? A) An apoptosis-promoting gene is put under the control of a high-efficiency promoter, increasing its expression. B) A tumor-suppressor gene is relocated to a region of increased gene expression. C) The sequence arrangement in the newly-fused chromosome leads to reduced expression for a proto-oncogene. D) The sequence arrangement in the newly-fused chromosome leads to overactive expression of a proto-oncogene.

Haplotype

The linkage of alleles or molecular markers along a single chromosome

Metastatic

The property that allows cancer cells to migrate to other parts of the body and cause secondary tumors

A) who are all affected by the same disease

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 ______. A) who are all affected by the same disease B) who have variations of the same disease C) including people who have the disease and those who do not D) who suffer from many different diseases

A) Sequence a candidate gene from both affected and unaffected individuals.

To determine which gene in a chromosomal region is responsible for a specific disease, which of the following steps would be used LAST? A) Sequence a candidate gene from both affected and unaffected individuals. B) Use published DNA sequences to identify 5-10 genes located in the chromosomal region identified by haplotype association studies. C) Identify a set of candidate genes with a haplotype association study. D) Determine whether a candidate gene is active in the cell type that would be affected by the disease.

B) phosphorylation of Rb protein so that it no longer binds to transcription factor E2F

Which event activates progression through the cell cycle? A) removal of a phosphate group from Rb protein so that it binds to transcription factor E2F B) phosphorylation of Rb protein so that it no longer binds to transcription factor E2F C) formation of a cyclin-CDK complex that removes a phosphate group from Rb protein D) phosphorylation of transcription factor E2F so that it no longer binds to Rb protein

An affected offspring can have two unaffected parents Two affected individuals must have affected children The trait occurs in the same frequency in both males and females

Which of the following features are characteristic of autosomal recessive inheritance? Multiple select question An affected offspring can have two unaffected parents. Two unaffected heterozygotes have on average 50% affected children. Two affected individuals must have affected children. An affected individual must have at least one affected parent. Males are affected more frequently than females. The trait occurs in the same frequency in both males and females.

C) The loss of tumor-suppressor genes on these chromosomes causes the cell to grow uncontrollably.

Which outcome is consistent with the genetic change that occurs when a cell loses both members of a homologous chromosome pair? A) The loss of oncogenes on these chromosomes causes the cell to grow uncontrollably. B) The loss of tumor-suppressor genes on these chromosomes inhibits cell growth. C) The loss of tumor-suppressor genes on these chromosomes causes the cell to grow uncontrollably. D) The loss of oncogenes on these chromosomes inhibits cell growth.

D) Unphosphorylated Rb protein prevents progress through the cell cycle by binding to transcription factor E2F.

What is the normal role of Rb protein during the process of cell division? A) Rb protein interacts with a cyclin-CDK complex to slow progress through the cell cycle. B) Phosphorylated Rb protein prevents progress through the cell cycle by binding to transcription factor E2F. C) Unphosphorylated Rb protein stimulates the action of transcription factor E2F, speeding up the cell cycle. D) Unphosphorylated Rb protein prevents progress through the cell cycle by binding to transcription factor E2F.

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

Choose the observations that are consistent with a disease having a genetic basis. Multiple select question A cancerous growth of immature nerve cells called neuroblastoma is associated with a deletion in a specific region of chromosome 11. Tay-Sachs disease can occur in 1/2500 births in a specific eastern European population while the frequency is 1/250,000 across Europe. The sleep disorder called narcolepsy has been linked to an allele for a faulty neural receptor in dogs. Some humans also suffer from narcolepsy. People from several different families living in a region with high levels of air pollution develop lower respiratory tract infections. Smokers are at high risk for developing lung cancer.

D) C

In this pedigree, individuals with Huntington disease are shown with filled symbols. The letters indicate which combination of four possible forms (A, B C, D) of a molecular marker called G8 that each person has inherited. Although there are some exceptions, the inheritance of Huntington disease is most closely associated with which form of the G8 marker in this pedigree? A) D B) B C) A D) C

initiate apoptosis stimulate the expression of the p21 gene to inhibit the G1 to S transition of the cell cycle activate genes involved with DNA repair

To prevent cells with damaged DNA from dividing, the tumor-suppressor protein p53 can ______. Multiple select question initiate apoptosis phosphorylate proteins to slow progress through the cell cycle stimulate the expression of the p21 gene to inhibit the G1 to S transition of the cell cycle activate genes involved with DNA repair

C) An epidermal growth factor, EGF, binds to a receptor on the surface of a skin cell.

To stimulate the growth of epidermal cells, such as skin cells, which event would occur first? A) MAPK activates transcription factors for genes promoting cell division. B) A multi-step intracellular signaling pathway leads to the activation of a protein kinase called MAPK. C) An epidermal growth factor, EGF, binds to a receptor on the surface of a skin cell.

Nephroblastoma is a cancer of the kidney that typically develops in children and is only rarely found in adults. 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. Someone with a diagnosis of retinitis pigmentosa has learned that there are family members in the preceding three generations who had the disease.

Which observations are consistent with a disease having a genetic basis? Multiple select question People from several different families living in a region with high levels of air pollution develop chronic obstructive pulmonary disease. People who have diets high in saturated fats are likely to develop atherosclerosis. Nephroblastoma is a cancer of the kidney that typically develops in children and is only rarely found in adults. 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. Someone with a diagnosis of retinitis pigmentosa has learned that there are family members in the preceding three generations who had the disease.