Test Bank for Chapter 23: Cancer GeneticsMultiple-Choice Questions1. Most cancers are assumed to arise through which of the following?a. Errors in transcriptionb. The production of unbalanced gametes because of nondisjunction during meiosis. c. Genetic or epigenetic changes in somatic cellsd. Delayed cell division during early embryogenesise. None of the above answers is correct. Answer: cSection: 23.1Comprehension Question2. Which of the following is the major event associated with the retinoblastoma cancer?a. A translocation involving chromosomes 9 and 22b. Both copies of a tumor-suppressor gene are inactivatedc. A translocation results in the enhanced expression of an oncogened. A mutation results in an activated RAS oncogenee. Inactivation of a major DNA repair systemAnswer: bSection: 23.1Comprehension Question3. Evidence that the development of cancer is a multistep process includes:a. The observation that certain tumor suppressor genes and oncogenes are involved in a sequential manner in the development of colon cancerb. The fact that proto-oncogenes are widely conserved in evolution c. The usual occurrence of retinoblastoma at a young age d. The development of a cancer as a result of activation of a single oncogene by any of a variety of mechanismse. The fact that there are many genetic and epigenetic mechanisms that lead to inactivation of the same tumor suppressor gene. Answer: a Section: 23.1Comprehension Question4. What specifically do most people inherit when they inherit a predisposition to a particular cancer such as retinoblastoma?a. A mutation that causes the over-expression of a DNA repair geneb. A mutation that causes telomerase to have reduced expression in somatic cellsc. A deleterious mutation in one copy of a tumor-suppressor gened. A deletion that removes one copy of an oncogenee. An extra X chromosome from the motherAnswer: cSection: 23.1Comprehension Question5. Which if the following types of cancer is associated with a defect in nucleotide-excision repair?a. Retinoblastomab. Xeroderma pigmentosumc. Cervical cancerd. Chronic myelogenous leukemiae. Bloom syndromeAnswer: bSection: 23.1Comprehension Question6. The process by which genetic changes occur in tumors and allows them to become increasingly aggressive over time is called?a. Clonal evolution b. Metastasis c. Loss of heterozygosityd. Epigenetic evolution e. Signal transductionAnswer: aSection: 23.1Comprehension Question 7. Which of the following is a process whereby cancer cells travel to other sites in the body and establish secondary tumors?a. Oncogenesisb. Angiogenesisc. Malignancyd. Secondary tumorigenesise. MetastasisAnswer: eSection: 23.1Comprehension Question8. Which of the following result(s) directly from metastasis?a. Primary tumorsb. Secondary tumorsc. Tumor vascularizationd. Decreased DNA repaire. Increased apoptosisAnswer: bSection: 23.1Comprehension Question9. Certain viruses are instrumental in converting proto-oncogenes to oncogenes. This conversion most commonly results because: a. Viruses specifically infect cells that contain proto-oncogenes.b. Only viruses contain genes that can convert proto-oncogenes into oncogenes.c. The proto-oncogenes are more likely to undergo mutation or recombination within a virus. d. Viruses contain the remainder part of the DNA that is added to the proto-oncogene to form the oncogene.Answer: cSection: 23.2Comprehension Question10. Mutations in proto-oncogenes are generally _________ whereas mutations in tumor-suppressor alleles are generally ______________.a. Deletions; duplicationsb. Recessive; dominantc. Duplications; deletionsd. Dominant; recessivee. Deletions; base-pair substitutionsAnswer: dSection: 23.2Comprehension Question11. Which cell cycle checkpoint is most responsible for the decision of the cell to commit to dividing?a. The S/G2 checkpointb. The G1/S checkpointc. The spindle-assembly checkpointd. The G2/M checkpointe. The G1/G2 checkpointAnswer: bSection: 23.2Comprehension Question12. Which of the following are regulatory molecules whose normal function is to inhibit gene expression, but which often have reduced activity in many tumor cells?a. Histonesb. miRNAsc. Reverse transcripitasesd. Growth factorse. KinasesAnswer: bSection: 23.2Comprehension Question13. Which of the following groups of proteins is NOT commonly known to include oncogenes?a. Transcription factorsb. Growth factorsc. Signal-transduction proteinsd. Ion channelse. Growth factor receptorsAnswer: dSection: 23.2Comprehension Question14. Genes that encode components of the cytoskeleton and extracellular matrix often contribute to which process?a. DNA repairb. Mutationc. Metastasisd. Primary tumor formatione. Signal transductionAnswer: cSection: 23.2Comprehension Question15. The p53 gene is important in controlling apoptosis, but it also plays a role in:a. Initiating mitosis.b. Controlling cell adhesion.c. Opening ion channels.d. duplicating the centrosome.e. Preventing aneuploidy by regulating the spindle-assembly checkpoint.Answer: dSection: 23.2Comprehension Question16. An abnormally low level of expression of a particular microRNA might facilitate the development of a cancer by which of the following methods?a. Inducing the increased expression of a tumor-suppressor geneb. Inducing the increased expression of DNA repair genec. Promoting an decreased level of telomerase activityd. Inhibiting the G1 to M transition in the cell cyclee. Increasing the expression of an oncogeneAnswer: eSection: 23.2Comprehension Question17. Many tumors are best described by which of the following?a. Abnormally high levels of telomerase expressionb. Abnormally high levels of tumor-suppressor gene expressionc. Translocations that move a tumor suppressor gene to a new location that increases its normal expressiond. Deletions that remove an oncogene from the genomee. DNA replication is inhibited when it would normally occurAnswer: aSection: 23.2Comprehension Question18. Normal cellular genes whose products are involved in facilitating cell division to occur underappropriate conditions are called?a. Proto-oncogenesb. Tumor-suppressor genesc. Passenger genesd. Inhibitor genese. Driver genesAnswer: aSection: 23.2Comprehension Question19. The increased levels of telomerase associated with many tumor cells likely promotes cancer by…a. Enhancing levels of DNA repair so that cells remain normal and have stable genomes andthus would be able to replicate their DNA and divide more often.b. Promoting