Test Bank to accompany Life The Science of Biology, Eleventh Edition Sadava, Hillis ,Heller, Hacker

Chapter 15: Gene Mutation and Molecular Medicine TEST BANK QUESTIONS Multiple Choice 1. Sequencing of a child’s genomic DNA reveals that the child is a heterozygote for a new mutation. This mutation appears in all of the cells tested from a variety of tissues (including skin, blood, and hair). The mutation is not found in either the mother or the father. Most likely, this is a new mutation that occurred in . a. somatic; one of the parents b. somatic; the child c. germ line; one of the parents d. germ line; both of the parents e. germ line; the child Answer: c Learning Outcome: 15.1.1.a Distinguish between somatic and germ-line mutations. Bloom’s Level: 4. Analyzing 2. People are often more concerned about germ line mutations than somatic ones because germ line mutations a. have phenotypic effects, whereas somatic mutations do not. b. affect more nucleotides than somatic mutations do. c. transitions, whereas somatic mutations are transversions. d. are transmitted to offspring, whereas somatic mutations are not. e. occur more frequently than somatic mutations. Answer: d Learning Outcome: 15.1.1.a Distinguish between somatic and germ-line mutations. Bloom’s Level: 3. Applying 3. One son of Great Britain’s Queen Victoria was born with the X-linked disease hemophilia, and two of her daughters were carriers, as some of their male children were born with hemophilia. King Albert did not have hemophilia, nor did any of Queen Victoria’s relatives on her mother’s side. Based on this information, the hemophilia mutation most likely originated a. as a somatic mutation in Queen Victoria. b. in a sperm cell from King Albert. c. as a somatic mutation in King Albert. d. in the egg from Queen Victoria’s mother. e. in the egg from King Albert’s mother. Answer: d Learning Outcome: 15.1.1.a Distinguish between somatic and germ-line mutations. Bloom’s Level: 5. Evaluating 4. Gain of function mutations a. are dominant mutations that are expressed in wild-type cells. b. are dominant mutations that are expressed in mutant cells. c. are the cause of continuous division in cancer cells. d. can be analyzed only under restrictive conditions. e. are expressed only with the appropriate environmental signals. Answer: b Learning Outcome: 15.1.1.b Identify examples of the following types of mutations: silent, loss-of-function, gain-of-function, conditional, and reversion. Bloom’s Level: 1. Remembering 5. If a mutation has a visible effect at 26°C, but no visible effect at 20°C, then 20°C is the temperature and 26°C is the temperature. a. permissive; conditional b. permissive; restrictive c. restrictive; conditional d. restrictive; permissive e. conditional; restrictive Answer: b Learning Outcome: 15.1.1.b Identify examples of the following types of mutations: silent, loss-of-function, gain-of-function, conditional, and reversion. Bloom’s Level: 2. Understanding 6. Because of the redundancy in the genetic code, many mutations in the coding regions of genes are a. transitions. b. transversions. c. inversions. d. somatic mutations. e. silent mutations. Answer: e Learning Outcome: 15.1.1.b Identify examples of the following types of mutations: silent, loss-of-function, gain-of-function, conditional, and reversion. Bloom’s Level: 2. Understanding 7. The isoenzyme hexosaminidase A (HEXA), composed of subunits α and β, breaks down molecules containing terminal N-acetyl hexosamines. Tay-Sachs disease is caused by a recessively inherited mutation in the gene coding for the α subunit, which is the subunit that hydrolyzes the lipid GM2 ganglioside. Accumulation of this lipid in the brain leads to progressive deterioration of the nervous system and death, usually by age 4. A child born homozygous for the loss-of-function α subunit allele nevertheless does not develop Tay-Sachs disease. Sequence analysis of the β subunit alleles reveals that one allele has a mutation that makes it able to hydrolyze GM2 ganglioside. This is a - of-function mutation, which is most likely . a. gain; dominant b. gain; recessive c. loss; dominant d. loss; recessive e. loss; intermediately dominant Answer: a Learning Outcome: 15.1.1.b Identify examples of the following types of mutations: silent, loss-of-function, gain-of-function, conditional, and reversion. Bloom’s Level: 4. Analyzing 8. Refer to the table.