front 1 The main reason scientists thought that proteins, rather than DNA, were the carriers of genetic material in the cell was: | back 1 the large number of possible amino acids combinations |
front 2 In the experiments of Griffith, the conversion of nonlethal R-strain bacteria to lethal S-strain bacteria: | back 2 was an example of the genetic exchange known as transformation |
front 3 The first experimenters to use Griffith's transformation assay to identify the genetic material were: | back 3 Avery, MacLeod, and McCarty |
front 4 Which of the following statements about DNA is false? | back 4 DNA is only found in eukaryotic cells |
front 5 The bacteriophages used in Alfred Hershey's and Martha Chase's experiments showed that: | back 5 DNA was injected into bacteria |
front 6 The two molecules that alternate to form the backbone of a polynucleotide chain are: | back 6 sugar and phosphate |
front 7 Chargaff determined that DNA from any source contains about the same amount of guanine as __________. | back 7 cytosine |
front 8 __________ used x-ray diffraction to provide images of DNA. | back 8 Franklin |
front 9 X-ray diffraction studies are used to determine: | back 9 the distances between atoms of molecules |
front 10 X-ray crystallography showed that DNA: | back 10 was a helix |
front 11 __________ determined the structure of the molecule DNA. | back 11 Waston and Crick |
front 12 The information carried by DNA is incorporated in a code specified by the: | back 12 specific nucleotide sequence of the DNA molecule |
front 13 Why is DNA able to store large amounts of information? | back 13 Its nucleotides can be arranged in a large number of possible sequences |
front 14 The portion of the molecule in box 5 of Figure 12-1 is: | back 14 a phosphate |
front 15 In Figure 12-1, the portion of the molecule in box __________ is a pyrimidine. | back 15 1 |
front 16 The portion of the molecule in box 3 of Figure 12-1 is: | back 16 a purine |
front 17 Hydrogen bonds can form between guanine and __________, and between adenine and __________. | back 17 cytosine; thymine |
front 18 Two chains of DNA must run in __________ direction(s) and must be __________ if they are to bond with each other. | back 18 antiparallel; complementary |
front 19 Which of the following nucleotide sequences represents the complement
to the DNA strand | back 19 3¢-TCTAGGC-5¢ |
front 20 When DNA copies itself, | back 20 the two stands separate and both serve as templates |
front 21 Which of the following best describes semiconservative replication? | back 21 A DNA molecule consists of one parental strand and one new strand |
front 22 The final product of DNA replication is: | back 22 two DNA molecules, each of which contains one new and one old DNA strand |
front 23 Who first confirmed that the replication of DNA was semiconservative? | back 23 Meselson and Stahl |
front 24 If DNA replication rejoined the 2 parental strands, it would be termed: | back 24 conservative |
front 25 Meselson and Stahl separated DNA from different generations using: | back 25 the mutation is corrected by the DNA polymerase enzyme |
front 26 When a DNA molecule containing a wrong base at one location in one strand is replicated: | back 26 The mutation is copied into one of the two daughter molecules |
front 27 Which of the following causes the unwinding of the DNA double helix? | back 27 DNA helicase |
front 28 A replication fork: | back 28 is a Y shaped structure where both DNA strands are replicated simultaneously |
front 29 In replication, once the DNA strands have been separated, reformation of the double helix is prevented by: | back 29 single strand binding proteins |
front 30 Enzymes called __________ form breaks in the DNA molecules to prevent the formation of knots in the DNA helix during replication. | back 30 topoisomerases |
front 31 What prevents knot formation in replicating DNA? | back 31 topoisomerase |
front 32 Which of the following adds new nucleotides to a growing DNA chain? | back 32 DNA polymerase |
front 33 Why does DNA synthesis only proceed in the 5¢ to 3¢ direction? | back 33 Because DNA polymerases can only add nucleotides to the 3c end of a polynucleotide strand |
front 34 The 5¢ end of each Okazaki fragment begins with: | back 34 A separate RNA primer |
front 35 DNA primase is the enzyme responsible for: | back 35 making short strands of RNA at the site of replication initiation |
front 36 The DNA strand that is replicated smoothly and continuously is called the: | back 36 leading strand |
front 37 In DNA replication, the lagging strand: | back 37 is synthesized as a series of Okazaki fragments |
front 38 Okazaki fragments are joined together by: | back 38 DNA ligase |
front 39 How is the chromosome of a bacterial cell replicated? | back 39 The circular DNA molecule is replicated from one origin of replication bidirectionally |
front 40 How are the chromosomes of a eukaryote cell replicated? | back 40 The linear DNA molecules are replicated from multiple origins of replication bidirectionally |
front 41 Refer to Figure 12-2. The correct designation for the DNA strand labeled C is: | back 41 A strand serving as a template |
front 42 Refer to Figure 12-2. The segments labeled F are responsible for: | back 42 initiating DNA synthesis |
front 43 Refer to Figure 12-2. The enzyme represented by the letter D is responsible for: | back 43 linking short DNA segments |
front 44 Refer to Figure 12-2. The structures represented by the letter E are called: | back 44 Okazaki fragments |
front 45 Which of the following statements concerning nucleotide excision repair is FALSE? | back 45 it is a type of mismatch repair |
front 46 __________, the ends of eukaryotic chromosomes, shorten with every cell replication event. | back 46 telomeres |
front 47 The ends of eukaryotic chromosomes can be lengthened by: | back 47 telomerase |
front 48 When cultured normal human cells were infected with a virus that carried the genes that coded for a subunit of telomerase: | back 48 the cells underwent more cell divisions than normal |
front 49 Cancerous cells differ from noncancerous cells in that cancerous cells: | back 49 can maintain telomere length as they divide |
front 50 Mismatch repair occurs when | back 50 enzymes remove incorrectly-paired nucleotides |