BIO203 Chapter 12 DNA

Okazaki fragments are joined together by: a. RNA polymerase. b. DNA ligase. c. DNA polymerase. d. RNA ligase. e. primase.

b. DNA ligase.

Meselson and Stahl separated DNA from different generations using: a. density gradient centrifugation. b. gel electrophoresis. c. an electron microscope. d. differential radioisotope labeling. e. None of these.

a

Which of the following statements concerning nucleotide excision repair is FALSE? a. It is a type of mismatch repair. b. It involves a nuclease. c. It involves a DNA polymerase. d. It involves DNA ligase. e. It is implicated in xeroderma pigmentosum.

a

Why does DNA synthesis only proceed in the 5¢ to 3¢ direction? a. Because DNA polymerases can only add nucleotides to the 3¢ end of a polynucleotide strand. b. Because the 3¢ end of the polynucleotide molecule is more electronegative than the 5¢ end. c. Because that is the direction in which the two strands of DNA unzip. d. Because that is the only direction that the polymerase can be oriented. e. Because the chromosomes are always aligned in the 5¢ to 3¢ direction in the nucleus

a. Because DNA polymerases can only add nucleotides to the 3¢ end of a polynucleotide

Which of the following adds new nucleotides to a growing DNA chain? a. DNA polymerase b. DNA helicase c. RNA primer d. primase e. RNA polymerase

a. DNA polymerase

The bacteriophages used in Alfred Hershey's and Martha Chase's experiments showed that: a. DNA was injected into bacteria. b. DNA and protein were injected into bacteria. c. DNA remained on the outer coat of bacteria. d. proteins were injected into bacteria. e. proteins were responsible for the production of new viruses within the bacteria

a. DNA was injected into bacteria.

How are the chromosomes of a eukaryote cell replicated? a. The linear DNA molecules are replicated from multiple origins of replication bidirectionally. b. The linear DNA molecules are replicated from one origin of replication bidirectionally. c. The circular DNA molecules are replicated from multiple origins of replication bidirectionally. d. The circular DNA molecules are replicated from one origin of replication bidirectionally. e. The linear DNA molecules are replicated from one origin of replication unidirectionally

a. The linear DNA molecules are replicated from multiple origins of replication bidirectionally.

__________ used x-ray diffraction to provide images of DNA. a. Watson and Crick b. Crick and Wilkins c. Franklin d. Franklin and Crick e. Watson and Wilkins

a. Watson and Crick

In DNA replication, the lagging strand: a. is synthesized as a series of Okazaki fragments. b. is synthesized as a complementary copy of the leading strand. c. pairs with the leading strand by complementary base pairing. d. is made up entirely of RNA primers. e. is not synthesized until the synthesis of the leading strand is completed

a. is synthesized as a series of Okazaki fragments.

When cultured normal human cells were infected with a virus that carried the genes that coded for a subunit of telomerase: a. the cells underwent more cell divisions than normal. b. the cells underwent fewer cell divisions than normal. c. the cells died almost immediately. d. the cells underwent gene expression more vigorously. e. the cell cycle shortened.

a. the cells underwent more cell divisions than normal.

Which of the following best describes semiconservative replication? a. The translation of a DNA molecule into a complementary strand of RNA. b. A DNA molecule consists of one parental strand and one new strand. c. The number of DNA molecules is doubled with every other replication. d. The replication of DNA never takes place with 100% accuracy. e. The replication of DNA takes place at a defined period in the cell cycle.

b. A DNA molecule consists of one parental strand and one new strand.

Which of the following causes the unwinding of the DNA double helix? a. DNA polymerase b. DNA helicase c. RNA primer d. primosome e. RNA polymerase

b. DNA helicase

Why is DNA able to store large amounts of information? a. It contains a large number of different nucleotides. b. Its nucleotides can be arranged in a large number of possible sequences. c. It is capable of assuming a wide variety of shapes. d. The sugar and phosphates can be arranged in many different sequences. e. The nucleotides can be altered to form many different letters in the sequence.

b. Its nucleotides can be arranged in a large number of possible sequences.

__________, the ends of eukaryotic chromosomes, shorten with every cell replication event. a. Centromeres b. Telomeres c. Kinetochores d. Primosomes e. Nucleosomes

b. Telomeres

__________ determined the structure of the molecule DNA. a. Crick and Wilkins b. Watson and Crick c. Franklin and Crick d. Franklin e. Watson, Crick, and Wilkins

b. Watson and Crick

In replication, once the DNA strands have been separated, reformation of the double helix is prevented by: a. DNA helicase enzyme. b. single-strand binding proteins. c. DNA polymerases. d. ATP. e. GTP

b. single-strand binding proteins.

In the experiments of Griffith, the conversion of nonlethal R-strain bacteria to lethal S-strain bacteria: a. was the result of genetic mutation. b. was an example of the genetic exchange known as transformation. c. supported the case for proteins as the genetic material. d. could not be reproduced by other researchers. e. was an example of conjugation

b. was an example of the genetic exchange known as transformation.

The first experimenters to use Griffith's transformation assay to identify the genetic material were: a. Meselson and Stahl. b. Watson and Crick. c. Franklin and Wilkins. d. Avery, MacLeod, and McCarty. e. Hershey and Chas

c. Franklin and Wilkins.

Hydrogen bonds can form between guanine and __________, and between adenine and __________. a. phosphate; sugar b. thymine; cytosine c. cytosine; thymine d. sugar; phosphate e. adenine; guanine

c. cytosine; thymine

A replication fork: a. is only seen in prokaryotic chromosomes. b. is only seen in bacterial cells. c. is a Y-shaped structure where both DNA strands are replicated simultaneously. d. is a site where one DNA strand serves as a template, but the other strand is not replicated. e. is created by the action of the enzyme RNA polymerase.

c. is a Y-shaped structure where both DNA strands are replicated simultaneously.

The DNA strand that is replicated smoothly and continuously is called the: a. primary strand. b. first strand. c. leading strand. d. alpha strand. e. lagging strand.

c. leading strand.

The two molecules that alternate to form the backbone of a polynucleotide chain are: a. adenine and thymine. b. cytosine and guanine. c. sugar and phosphate. d. base and sugar. e. base and phosphate

c. sugar and phosphate.

X-ray diffraction studies are used to determine: a. the sequence of amino acids in protein molecules. b. the sequence of nucleic acids in nucleic acid molecules. c. the distances between atoms of molecules. d. the type of chemical under investigation. e. the wavelength of light emitted by chemicals

c. the distances between atoms of molecules.

The main reason scientists thought that proteins, rather than DNA, were the carriers of genetic material in the cell was: a. their presence within the nucleus. b. their abundance within the cell. c. the large number of possible amino acid combinations. d. their ability to self replicate within the cytoplasm. e. their ability to be exported from the cell.

c. the large number of possible amino acid combinations.

When a DNA molecule containing a wrong base at one location in one strand is replicated: a. the mutation is corrected by the DNA polymerase enzyme. b. the mutation is ignored by the DNA polymerase enzyme. c. the mutation is copied into one of the two daughter molecules. d. the mutation is copied into both of the daughter molecules. e. the replication is stopped.

c. the mutation is copied into one of the two daughter molecules.

If DNA replication rejoined the 2 parental strands, it would be termed: a. dispersive. b. gradient. c. semiconservative. d. parental. e. conservative

conservative

Which of the following statements about DNA is false? a. DNA is capable of forming many different sequences. b. DNA contains thymine instead of uracil. c. DNA is double-stranded rather than single-stranded. d. DNA is only found in eukaryotic cells. e. DNA contains the sugar deoxyribose.

d. DNA is only found in eukaryotic cells.

Who first confirmed that the replication of DNA was semiconservative? a. Chargaff and Hershey b. Watson and Crick c. Avery and Griffith d. Meselson and Stahl e. Watson, Crick, and Wilkins

d. Meselson and Stahl

How is the chromosome of a bacterial cell replicated? a. The linear DNA molecule is replicated from multiple origins of replication bidirectionally. b. The linear DNA molecule is replicated from one origin of replication bidirectionally. c. The circular DNA molecule is replicated from multiple origins of replication bidirectionally. d. The circular DNA molecule is replicated from one origin of replication bidirectionally. e. The circular DNA molecule is replicated from one origin of replication unidirectionally

d. The circular DNA molecule is replicated from one origin of replication bidirectionally.

The 5¢ end of each Okazaki fragment begins with: a. the same RNA primer that began synthesis on the leading strand. b. a DNA primer binding to the template DNA. c. DNA polymerase binding to the template DNA. d. a separate RNA primer. e. a small DNA primer.

d. a separate RNA primer.

Cancerous cells differ from noncancerous cells in that cancerous cells: a. have reduced levels of telomerase. b. divide only 20 to 30 times. c. have lost the ability to resist apoptosis. d. can maintain telomere length as they divide. e. lack telomeres.

d. can maintain telomere length as they divide.

Chargaff determined that DNA from any source contains about the same amount of guanine as __________. a. uracil b. thymine c. adenine d. cytosine e. guanine

d. cytosine

Primase is the enzyme responsible for: a. unwinding the DNA double strand to allow DNA polymerase access to the template DNA. b. introducing nicks into the DNA double strand in order to prevent the formation of knots. c. hydrolyzing ATP to facilitate DNA unwinding. d. making short strands of RNA at the site of replication initiation. e. forming a replication fork in the DNA double helix.

d. making short strands of RNA at the site of replication initiation.

The information carried by DNA is incorporated in a code specified by the: a. phosphodiester bonds of the DNA strand. b. number of separate strands of DNA. c. size of a particular chromosome. d. specific nucleotide sequence of the DNA molecule. e. number of bases in a DNA strand.

d. specific nucleotide sequence of the DNA molecule.

The ends of eukaryotic chromosomes can be lengthened by: a. apoptosis. b. reverse transcriptase. c. primase. d. telomerase. e. DNA polymeras

d. telomerase.

The final product of DNA replication is: a. mRNA, tRNA, and rRNA molecules. b. a wide variety of proteins. c. DNA fragments. d. two DNA molecules, each of which contains one new and one old DNA strand. e. the enzymes needed for further processes, such as DNA polymerase

d. two DNA molecules, each of which contains one new and one old DNA strand.

Which of the following nucleotide sequences represents the complement to the DNA strand 5¢ - AGATCCG- 3¢? a. 5¢ - AGATCCG- 3¢ b. 3¢ - AGATCCG- 5¢ c. 5¢ - CTCGAAT- 3¢ d. 3¢ - CTCGAAT- 5¢ e. 3¢ - TCTAGGC- 5¢

e. 3¢ - TCTAGGC- 5¢

How is a single strand of DNA able to serve as a template for the synthesis of another strand? a. Nucleotides pair with those of the original strand to form a new strand. b. Hydrogen bonds holding the two strands together are easy to break, allowing one strand to be a template. c. A single strand of DNA is not able to serve as a template. d. One strand of DNA directs the synthesis of a new strand on its partner. e. Both the pairing of nucleotides and the breaking of hydrogen bonds

e. Both the pairing of nucleotides and the breaking of hydrogen bonds

Two chains of DNA must run in __________ direction(s) and must be __________ if they are to bond with each other. a. the same; uncomplementary b. opposite; uncomplementary c. parallel; uncomplementary d. parallel; complementary e. antiparallel; complementary

e. antiparallel; complementary

X-ray crystallography showed that DNA: a. had the bases in the center of the molecule. b. had the sugars and phosphates on the outside of the molecule. c. was a very long molecule. d. was made of 2 strands. e. was a helix.

e. was a helix.

Enzymes called __________ form breaks in the DNA molecules to prevent the formation of knots in the DNA helix during replication. a. topoisomerases b. single-strand binding proteins c. DNA polymerases d. RNA polymerases e. DNA ligases

topoisomerases