Chapter 9 Preview - DNA

Size: px
Start display at page:

Download "Chapter 9 Preview - DNA"

Transcription

1 Chapter 9 Preview - DNA Multiple Choice Identify the choice that best completes the statement or answers the question. 1. In order to show that DNA in cell extracts is responsible for genetic transformation in of bacteria, important corroborating evidence should indicate that also destroyed transforming activity. a. enzymes that hydrolyzed proteins b. enzymes that hydrolyzed DNA c. enzymes that hydrolyzed polysaccharides d. boilinge. enzymes that hydrolyze RNA. 2. If adenine makes up 20 percent of the bases in a sample of double-stranded DNA, what percentage of the bases would be uracil? a. 0 b. 10 c. 15 d. 20 e If guanine makes up 20 percent of the bases in a sample of double-stranded DNA, what percentage of the bases would be cytosine? a. 15 b. 20 c. 30 d. 40 e If adenine makes up 20 percent of the bases in a sample of double-stranded DNA, what percentage of the bases would be cytosine? a. 15 b. 30 c. 35 d. 40 e Which of the following statements about DNA structure is false? a. The 3' end is phosphorylated. b. It is a double-stranded helix. c. It has a uniform diameter. d. It is a right-handed helix. e. It is antiparallel (the two strands run in opposite directions). 6. A-T base pairs in a DNA double helix a. are not accessible to DNA binding proteins. b. form three hydrogen bonds with each other. c. are of a different length than G-C base pairs. d. are more heat stable than G-C base pairs. e. are chemically distinct from G-C base pairs. 7. The 5' end of a DNA strand a. is part of the template strand during DNA replication.

2 b. does not contain a phosphate group on the ribose. c. is part of the growing strand during DNA replication. d. is the end of both strands of DNA in a double helix. e. could contain the base, uridine. 8. Which of the following is not used for DNA synthesis? a. dctp b. dttp c. dutp d. dgtp e. datp 9. The replication of lagging strands of DNA differs from the replication of leading strands in that a. DNA is replicated as short fragments. b. RNA primers are required. c. DNA ligase is needed. d. primase is required. e. All of the above 10. In many eukaryotes, there are repetitive sequences at the ends of chromosomes called telomeres. After successive rounds of DNA replication, the strand becomes shorter. In some cells, an enzyme called repairs the shortened strand. a. lagging; telomerase b. leading; DNA polymerase I c. leading; replicase d. lagging; DNA polymerase I e. leading; telomerase 11. Which of the following statements about repairing errors in DNA replication is false? a. During DNA replication, guanine may be incorrectly paired with thymine, requiring repair. b. After replication, mismatch repair proteins excise a small portion of the DNA molecule that includes the mismatched bases. c. DNA polymerase I replaces the removed section of DNA with the correct bases. d. DNA topoisomerase repairs the remaining nicks in the newly replicated strand. e. During DNA replication, DNA polymerase proofreads the growing strand and replaces incorrectly paired nucleotides before continuing replication. 12. The polymerase chain reaction requires a. one specific DNA oligonucleotide as a primer. b. single-stranded DNA as a template. c. a heat resistant RNA polymerase. d. cyclical denaturation and binding of double-stranded DNA. e. primase. 13. In multicellular organisms a. somatic mutations are passed on to offspring produced by sexual reproduction. b. somatic mutations may be passed to daughter cells by mitosis. c. all mutations produce phenotypic changes. d. meiosis is not required for the transmission of germ line mutations to the next generation. e. all mutations are point mutations. 14. Mutations

3 a. are always deleterious. b. can arise from errors in DNA replication. c. are always caused by mutagens d. occur at the same rate for all bases. e. are of no importance to evolution. 15. A silent mutation a. is a result of a change in a codon for an amino acid in a protein to a stop codon. b. results in a shorter mrna transcript of the gene. c. results in a protein that is truncated from the N-terminal end. d. would likely not affect the activity of a protein. e. would not affect the primary structure of a protein. 16. A mutant strain of yeast grew well at 20 C, but not at 37 C, whereas the wild-type strain grew well at both temperatures. The mutation is an example of a a. conditional mutation. b. missense mutation. c. point mutation. d. frame-shift mutation. e. gain-of-function mutation. 17. A point mutation a. is a result of a chromosomal deletion. b. is always silent. c. does not occur in noncoding regions of DNA. d. is a change in a single nucleotide of DNA. e. is not transmitted to daughter cells. 18. Which of the following mutations is not a chromosomal mutation? a. Large deletions b. Inversions c. Point mutations d. Translocations e. Duplications 19. Which of the following mechanisms does not cause spontaneous mutations to occur? a. Errors during DNA replication b. Errors during meiosis c. Spontaneous chemical reactions during DNA replication d. DNA pairing with the wrong base e. A mutagen causing a permanent change in DNA sequence 20. Which of the following mutagens may result in an induced mutation? a. Ultraviolet radiation b. Benzopyrene c. Aflatoxin d. Free radicals e. All of the above

4 Chapter 9 Preview - DNA Answer Section MULTIPLE CHOICE 1. ANS: B PTS: 1 REF: Page 167 SKL: 2. Understanding 2. ANS: A PTS: 1 REF: Page 169 SKL: 4. Analyzing 3. ANS: B PTS: 1 REF: Page 169 SKL: 3. Applying 4. ANS: B PTS: 1 REF: Page 169 SKL: 4. Analyzing 5. ANS: A PTS: 1 REF: Page SKL: 2. Understanding 6. ANS: E PTS: 1 REF: Page Page 172 Concept 9.2 DNA Replicates Semiconservatively SKL: 2. Understanding 7. ANS: C PTS: 1 REF: Page ANS: C PTS: 1 REF: Page 173 TOP: Concept 9.2 DNA Replicates Semiconservatively SKL: 1. Remembering 9. ANS: E PTS: 1 REF: Page ANS: A PTS: 1 REF: Page ANS: D PTS: 1 REF: Page ANS: D PTS: 1 REF: Page TOP: Concept 9.2 DNA Replicates Semiconservatively SKL: 4. Analyzing 13. ANS: B PTS: 1 REF: Page ANS: B PTS: 1 REF: Page ANS: D PTS: 1 REF: Page ANS: A PTS: 1 REF: Page ANS: D PTS: 1 REF: Page TOP: Concept 9.3 Mutations Are Heritable Changes in DNA SKL: 1. Remembering 18. ANS: C PTS: 1 REF: Page ANS: E PTS: 1 REF: Page

5 20. ANS: E PTS: 1 REF: Page