Review Questions
4. If DNA of a particular species was analyzed and it was found that it contains 27 percent A, what would be the percentage of C?
- 27 percent
- 30 percent
- 23 percent
- 54 percent
5. The experiments by Hershey and Chase helped confirm that DNA was the hereditary material on the basis of the finding that:
- radioactive phage were found in the pellet
- radioactive cells were found in the supernatant
- radioactive sulfur was found inside the cell
- radioactive phosphorus was found in the cell
6. Bacterial transformation is a major concern in many medical settings. Why might health care providers be concerned?
- Pathogenic bacteria could introduce disease-causing genes in non-pathogenic bacteria.
- Antibiotic resistance genes could be introduced to new bacteria to create “superbugs.”
- Bacteriophages could spread DNA encoding toxins to new bacteria.
- All of the above.
7. DNA double helix does not have which of the following?
- antiparallel configuration
- complementary base pairing
- major and minor grooves
- uracil
8. In eukaryotes, what is the DNA wrapped around?
- single-stranded binding proteins
- sliding clamp
- polymerase
- histones
9. Meselson and Stahl’s experiments proved that DNA replicates by which mode?
- conservative
- semi-conservative
- dispersive
- none of the above
10. If the sequence of the 5′-3′ strand is AATGCTAC, then the complementary sequence has the following sequence:
- 3′-AATGCTAC-5′
- 3′-CATCGTAA-5′
- 3′-TTACGATG-5′
- 3′-GTAGCATT-5′
11. How did Meselson and Stahl support Watson and Crick’s double-helix model?
- They demonstrated that each strand serves as a template for synthesizing a new strand of DNA.
- They showed that the DNA strands break and recombine without losing genetic material.
- They proved that DNA maintains a double-helix structure while undergoing semi-conservative replication.
- They demonstrated that conservative replication maintains the complementary base pairing of each DNA helix.
12. Which of the following components is not involved during the formation of the replication fork?
- single-strand binding proteins
- helicase
- origin of replication
- ligase
13. Which of the following does the enzyme primase synthesize?
- DNA primer
- RNA primer
- Okazaki fragments
- phosphodiester linkage
14. In which direction does DNA replication take place?
- 5′-3′
- 3′-5′
- 5′
- 3′
15. A scientist randomly mutates the DNA of a bacterium. She then sequences the bacterium’s daughter cells, and finds that the daughters have many errors in their replicated DNA. The parent bacterium likely acquired a mutation in which enzyme?
- DNA ligase
- DNA pol II
- Primase
- DNA pol I
16. The ends of the linear chromosomes are maintained by
- helicase
- primase
- DNA pol
- telomerase
17. Which of the following is not a true statement comparing prokaryotic and eukaryotic DNA replication?
- Both eukaryotic and prokaryotic DNA polymerases build off RNA primers made by primase.
- Eukaryotic DNA replication requires multiple replication forks, while prokaryotic replication uses a single origin to rapidly replicate the entire genome.
- DNA replication always occurs in the nucleus.
- Eukaryotic DNA replication involves more polymerases than prokaryotic replication.
18. During proofreading, which of the following enzymes reads the DNA?
- primase
- topoisomerase
- DNA pol
- helicase
19. The initial mechanism for repairing nucleotide errors in DNA is ________.
- mismatch repair
- DNA polymerase proofreading
- nucleotide excision repair
- thymine dimers
20. A scientist creates fruit fly larvae with a mutation that eliminates the exonuclease function of DNA pol. Which prediction about the mutational load in the adult fruit flies is most likely to be correct?
- The adults with the DNA pol mutation will have significantly more mutations than average.
- The adults with the DNA pol mutation will have slightly more mutations than average.
- The adults with the DNA pol mutation will have the same number of mutations as average.
- The adults with the DNA pol mutation will have fewer mutations than average.