Back
Problem 1
Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
RB1 (retinoblastoma)Problem 1
Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
p53 (Li–Fraumeni syndrome)Problem 1
Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
Which of these genes would you classify as a proto-oncogene and which as a tumor suppressor gene? Explain your categorization for each gene.Problem 1
Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
APC (familial adenomatous polyposis)Problem 1
Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
c-MYC (Burkitt lymphoma)Problem 1
Identify two general ways chemical mutagens can alter DNA. Give examples of these two mechanisms.
Problem 2
Go online to the Online Mendelian Inheritance of Man (OMIM) website. Look up the following genetic conditions and answer the questions posed about them.
Look up Tay–Sachs disease (TSD), OMIM number 272800, and give the name and abbreviation of the affected gene and the chromosome location of the gene.Problem 2
Go online to the Online Mendelian Inheritance of Man (OMIM) website. Look up the following genetic conditions and answer the questions posed about them.
Go to the 'Population Genetics' section discussing the TSD gene. In a few sentences, summarize the human population in which TSD is most frequently found and give the approximate frequency of heterozygous carriers for the TSD mutation in North American Jews.Problem 2
Go online to the Online Mendelian Inheritance of Man (OMIM) website. Look up the following genetic conditions and answer the questions posed about them.
Look up cystic fibrosis (CF), OMIM 602421, and give the gene name and abbreviation and the chromosome location of the gene.Problem 2
Go online to the Online Mendelian Inheritance of Man (OMIM) website. Look up the following genetic conditions and answer the questions posed about them.
Go to the 'Molecular Genetics' section and describe the most common mutation of the CF gene.Problem 2
Nitrous acid and 5-bromodeoxyuracil (BrdU) alter DNA by different mechanisms. What type of mutation does each compound produce?
Problem 3
What is the difference between a transition mutation and a transversion mutation?
Problem 3
When working on barley plants, two researchers independently identify a short-plant mutation and develop homozygous recessive lines of short plants. Careful measurements of the height of mutant short plants versus normal tall plants indicate that the two mutant lines have the same height. How would you determine if these two mutant lines carry mutation of the same gene or of different genes?Problem 3
For the retinal cancer retinoblastoma, the inheritance of one mutated copy of RB1 from one of the parents is often referred to as a mutation that produces a 'dominant predisposition to cancer.' This means that the first mutation does not produce cancer but makes it very likely that cancer will develop.
Explain why cancer is almost certain to develop with the inheritance of one mutated copy of RB1.Problem 4
What are the differences between a synonymous mutation, a missense mutation, and a nonsense mutation?
Problem 4
Explain the following processes involving chromosome mutations and cancer development.
How the chromosome mutation producing the Philadelphia chromosome leads to CML.Problem 4
Explain the following processes involving chromosome mutations and cancer development. How the chromosome mutation producing Burkitt lymphoma generates the disease.Problem 5
In March 2011 an earthquake measuring approximately 9.0 on the Richter scale struck Fukushima, Japan. Several nuclear reactors at the Fukushima Daichii Nuclear Power Plant were damaged, and nuclear core meltdown occurred. A massive release of radiation accompanied damage to the plant, and 5 years later the incidence of thyroid cancer in children exposed to the radiation was determined to be well over 100 times more frequent than expected without radiation exposure. DNA damage and mutations resulting from radiation exposure are suspected of causing this increased cancer rate. What gene discussed in this chapter might be responsible for pausing the cell cycle of dividing cells long enough for radiation-induced damage to be repaired in cells?Problem 5
In March 2011 an earthquake measuring approximately 9.0 on the Richter scale struck Fukushima, Japan. Several nuclear reactors at the Fukushima Daichii Nuclear Power Plant were damaged, and nuclear core meltdown occurred. A massive release of radiation accompanied damage to the plant, and 5 years later the incidence of thyroid cancer in children exposed to the radiation was determined to be well over 100 times more frequent than expected without radiation exposure. DNA damage and mutations resulting from radiation exposure are suspected of causing this increased cancer rate. Do you think it is possible that significant increases in the incidence of other types of cancer will occur in the future among people who were exposed to the Fukushima radiation? Why?Problem 5
UV irradiation causes damage to bacterial DNA. What kind of damage is frequently caused and how does photolyase repair the damage?
Problem 6
Ultraviolet (UV) radiation is mutagenic.
How do UV-induced DNA lesions lead to mutation?Problem 6
Ultraviolet (UV) radiation is mutagenic.
Identify and describe two DNA repair mechanisms that remove UV-induced DNA lesions.Problem 6
Ultraviolet (UV) radiation is mutagenic.
What kind of DNA lesion does UV energy cause?Problem 7
Researchers interested in studying mutation and mutation repair often induce mutations with various agents. What kinds of gene mutations are induced by
chemical mutagens? Give two examples.Problem 7
Researchers interested in studying mutation and mutation repair often induce mutations with various agents. What kinds of gene mutations are induced by
radiation energy? Give two examples.Problem 8
The effect of base-pair substitution mutations on protein function varies widely from no detectable effect to the complete loss of protein function (null allele). Why do the functional consequences of base-pair substitution vary so widely?
Problem 9
The human genome contains a large number of pseudogenes. How would you distinguish whether a particular sequence encodes a gene or a pseudogene? How do pseudogenes arise?
Problem 9
Describe the purpose of the Ames test. How are his⁻ bacteria used in the Ames test? What mutational event is identified using his⁻ bacteria?
Problem 10
In numerous population studies of spontaneous mutation, two observations are made consistently: (1) Most mutations are recessive, and (2) forward mutation is more frequent than reversion. What do you think are the likely explanations for these two observations?
Problem 10
Discuss the advantages (and possible disadvantages) of the different mutagens in Table 14.1.
