Download Multiple Choice. ______1. Which of the following molecules

Multiple Choice.
______1. Which of the following molecules functions to transfer information from one generation to
the next in eukaryotes?
a. DNA
b. mRNA
c. tRNA
d. Proteins
______2. Information sources used by Watson and Crick to determine the structure of DNA
included
a. electron micrographs of individual DNA molecules.
b. light micrographs of bacteriophage particles.
c. nuclear magnetic resonance analysis of DNA.
d. X-ray crystallography of double-stranded DNA.
______3. The DNA isolated from a newly discovered virus is found to be 32 percent A, 18 percent C,
18 percent G, and 32 percent T. The base composition of the complementary DNA would be
_______ percent A, _______ percent C, _______ percent G, and _______ percent T.
a. 32; 18; 18; 32
b. 19; 32; 17; 32
c. 17; 32; 32; 19
d. 25; 25; 25; 25
______4. Which of the following statements about infection of E. coli cells by bacteriophage T2 is
true?
a. Proteins are the only phage components that enter the infected cell.
b. Both proteins and nucleic acids enter the cell.
c. Only protein from the infecting phage can be detected in progeny phage.
d. Only nucleic acids enter the cell.
______5. The strands that make up DNA are antiparallel. This means that
a. one strand is positively charged, and the other is negatively charged.
b. the base pairings create unequal spacing between the two DNA strands.
c. the 5′-to-3′ direction of one strand is counter to the 5′-to-3′ direction of the other strand.
d. purines bond with purines and pyrimidines bond with pyrimidines.
______6. Within the DNA double helix, the nitrogenous bases are held together by
a. weak van der Waals forces.
b. covalent bonds.
c. hydrogen bonds.
d. Both a and b
______7. A strand of DNA with the sequence 5′-ATTCCG-3′ would have a complementary strand
with the sequence
a. 5′-CGGAAT-3′.
b. 5′-ATTCCG-3′.
c. 5′-ACCTTA-3′.
d. 5′-GCCTTA-3′.
______8. At the end of DNA replication, two DNA molecules are produced, each one consisting of a
parental DNA strand and a new DNA strand. This process is known as
a. conservative replication.
b. semiconservative replication.
c. dispersive replication
d. the transforming principle.
______9. In DNA replication, each newly made strand is
a. identical in DNA sequence to the strand from which it was copied.
b. complementary in sequence to the strand from which it was copied.
c. oriented in the same 3′-to-5′ direction as the strand from which it was copied.
d. an incomplete copy of one of the parental strands.
______10. Which of the following statements about DNA replication in eukaryotes and in
prokaryotes is true?
a. In eukaryotes, synthesis of the new DNA strand is from 3′ to 5′, whereas in prokaryotes it is from 5′
to 3′.
b. In eukaryotes, synthesis of the new DNA strand is from 5′ to 3′, whereas in prokaryotes it is from 3′
to 5′.
c. There are many replication forks in each eukaryotic chromosome and only one in prokaryotic DNA.
d. Okazaki fragments are produced in eukaryotic DNA replication but not in prokaryotic DNA
replication.
______11. The enzyme DNA ligase is required continuously during DNA replication because
a. fragments of the leading strand must be joined together.
b. fragments of the lagging strand must be joined together.
c. the parental strands must be joined back together.
d. the complex of proteins that work together at the replication fork must be prevented from falling
apart.
______12. The first repair of mistakes during DNA replication is made by
a. the mismatch repair system.
b. RNA polymerase.
c. DNA ligase.
d. DNA polymerase
______13. In sickle-cell disease, one amino acid is substituted for another. This type of mutation is
referred to as a _______ mutation.
a. nonsense
b. missense
c. frame-shift
d. silent
______14. Mutations
a. are always deleterious.
b. can arise from errors in DNA replication.
c. are always caused by mutagens.
d. are of no importance to evolution.
______15. Which of the following statements about the flow of genetic information is true?
a. Proteins encode information that is used to produce other proteins of the same amino acid
sequence.
b. RNA encodes information that is translated into DNA, and DNA encodes information that is
translated into proteins.
c. Proteins encode information that can be translated into RNA, and RNA encodes information that
can be transcribed into DNA.
d. DNA encodes information that is transcribed into RNA, and RNA encodes information that is
translated into proteins.
______16. Which of the following is not required for transcription?
a. A DNA template
b. DNA polymerase
c. RNA polymerase
d. All of the above are required for transcription.
______17. RNA polymerase is a
a. polysaccharide.
b. lipid.
c. protein.
d. nucleic acid.
______18. The transcription initiation site is located
a. within the promoter.
b. on RNA polymerase.
c. at splice sites.
d. in a ribosome.
______19. If a 5′-to-3′ coding strand of DNA has the sequence GTCTATGCATTA, what would be the
sequence of the resulting transcribed RNA?
a. 5′-GTCTATGCATTA-3′
b. 5′-GUCUAUGCAUUA-3′
c. 5′-CAGATACGTAAT-3′
d. 3′-GUCUAUGCAUUA-5′
______20. In eukaryotes, exons are
a. spliced out of the original transcript.
b. spliced together from the original transcript.
c. spliced to introns to form the final transcript.
d. usually much larger than introns.
______21. Which of the following statements about the genetic code is true?
a. Eukaryotes, archaea, and bacteria each evolved the genetic code independently.
b. The common ancestor of eukaryotes and archaea evolved the genetic code independently from the
one evolved by bacteria.
c. The common ancestor of eukaryotes and bacteria evolved the genetic code independently from the
one evolved by archaea.
d. The genetic code evolved in the common ancestor of all known life.
______22. UGU and UGC both code for cysteine. A change from UGU to UGC would thus be a
_______ mutation.
a. missense
b. nonsense
c. silent
d. frame-shift
______23. Which of the following statements about tRNAs is false?
a. Any particular tRNA binds to one and only one amino acid.
b. The three-dimensional structure of tRNA results from hydrogen bonding between complementary
bases.
c. tRNAs interact with ribosomes.
d. All of the above are true; none is false.
______24. Sickle-cell anemia results from a point mutation in the HBB gene. The mutation results
in the replacement of an amino acid that has a hydrophilic R-group with an amino acid that has a
hydrophobic R-group on the exterior of the hemoglobin protein. Such a mutation would most likely
result in altered
a. properties of the hemoglobin molecule as the result of abnormal interactions between adjacent
hemoglobin molecules
b. DNA structure as a result of abnormal hydrogen bonding between nitrogenous bases
c. fatty acid structure as a result of changes in ionic interactions between adjacent fatty acid chains
d. protein secondary structure as a result of abnormal hydrophobic interactions between R-groups in
the backbone of the protein
______25. At which of the following sites on the ribosome is the tRNA never charged (not carrying
an amino acid)?
a. A
b. P
c. E
d. Both a and b
______26. Stop codons terminate translation
a. by means of RNA polymerase activity.
b. by binding a protein release factor, causing hydrolysis of the bond between the polypeptide chain
and the tRNA.
c. by binding a signal sequence, causing hydrolysis of the bond between the polypeptide chain and the
tRNA.
d. tRNA molecule brings a stop amino acid, thus leading to the ribosome’s secretion of protein release
factors.
______27. A polyribosome is
a. a signal sequence.
b. the structure formed when multiple peptide chains are gathered together.
c. a protein release factor.
d. the structure formed when multiple ribosomes are translating an mRNA molecule.
______28. Put the following four steps of eukaryotic gene expression in order, from beginning to
end.
(1) Pre-mRNA is processed to make mRNA.
(2) Ribosomes translate the mRNA message to make proteins.
(3) mRNA is transported to the cytoplasm.
(4) DNA is used as a template make pre-mRNA.
a. 1; 4; 3; 2
b. 4; 3; 1; 2
c. 4; 1; 3; 2
d. 4; 1; 2; 3
______29. Transcription in prokaryotic cells
a. occurs in the nucleus, whereas translation occurs in the cytoplasm.
b. is initiated at a promoter and uses only one strand of DNA (the template strand) to synthesize a
complementary RNA strand.
c. is terminated at a stop codon.
d. is initiated at an ori site on the chromosome.
______30. A transcription factor is a _______ that binds to _______.
a. protein; DNA
b. protein; RNA
c. promoter; a protein
d. gene; DNA
______31. Which of the following would lead to an increase in the expression (or inappropriate
expression) of gene X?
a. A mutation that lowers the efficiency of a repressor of gene X
b. A mutation that lowers the efficiency of an activator of gene X
c. A mutation that increases the efficiency of a repressor of gene X
d. Both a and c
______32. Viruses
a. arise from preexisting viruses.
b. replicate their DNA before they reproduce.
c. develop and reproduce only within the cells of hosts.
d. cannot replicate.
______33. If a virus is in the lysogenic phase, it will
a. integrate its DNA into the host cell chromosome.
b. excise its DNA from the host cell chromosome.
c. lyse or cut open the host cell.
d. induce point mutations in the host cell.
______34. Retroviruses such as HIV
a. have DNA as their genome.
b. are prophages.
c. copy their RNA genome into DNA using reverse transcriptase.
d. replicate their genome using RNA polymerase.
______35. Which of the following statements about prokaryotes is true?
a. They generally live in static environments.
b. The most efficient means of regulation of gene expression in these organisms is usually at the level
of transcription.
c. By making certain proteins only when needed, they save energy and other resources.
d. Both a and b
e. Both b and c
______36. Which of the following statements about operons is false?
a. The structural genes in the operon are either all on or all off at a given time.
b. They consist of a cluster of genes with a single promoter.
c. They are the units of transcriptional regulation in prokaryotes.
d. All of the above are true; none is false.
______37. In the absence of substance M, a hypothetical LM operon is turned off. If substance M is
abundant, it can bind to the repressor, which permits the polymerase to begin transcribing the DNA.
In this case, LM is a(n) _______ operon and M acts as a(n) _______.
a. repressible; inducer
b. repressible, transcription factor
c. inducible; inducer
d. inducible; transcription factor
______38. Ribosomes are the structures in which
a. chemical energy is stored in the form of ATP.
b. cell division is controlled.
c. genetic information is used to make proteins.
d. sunlight energy is converted into chemical energy.
______39. Transcription of eukaryotic genes requires
a. binding of RNA polymerase to the promoter.
b. binding of several transcription factors.
c. capping of mRNA.
d. Both a and b
______40. The expression of some genes can be regulated in part by the pattern of alternative
splicing. This is an example of
a. DNA methylation.
b. pre-transcriptional regulation.
c. catalytic RNA activity.
d. Post-transcriptional control.
______43. In Drosophila and many other insects, the regions near the centromeres of most
chromosomes are largely heterochromatin. These regions, therefore, are likely to be _______
methylated and to have _______ gene activity.
a. heavily; low to no
b. heavily; high
c. variably; high
d. lightly; high
______44. A nucleotide in DNA is made up of
a. four bases.
b. a base plus a ribose sugar.
c. a base plus a deoxyribose sugar plus phosphate.
d. a sugar plus a phosphate.
______45. RNA differs from DNA in that RNA
a. is single-stranded, whereas DNA is double-stranded.
b. is an intermediate in information transfer, whereas DNA encodes hereditary information.
c. contains ribose, whereas DNA contains deoxyribose.
d. All of the above
______46. Single-stranded RNA can fold in on itself, creating three-dimensional structures for the
bonding and recognition of other molecules. The folds are stabilized by _______ bonds.
a. hydrogen
b. ionic
c. phosphodiester
d. peptide
47. Matching: Match the scientists to the experiments/scientific research they are known for
_____a. Hershey and Chase
1. Used X-ray Crystallography
_____b. Griffith
2. % A = % T in a sample of DNA
_____c. Avery, MaCarty and MaCleod
3. Made the first 3-D model of DNA
_____d. Rosalind Franklin
4. Found that injecting Heat-exposed S strain and
harmless R strain into mice resulted in death of the mice
_____e. Chargoff
5. Purified protein and DNA were injected separately into
bacteria and found that only the DNA injection
successfully transformed bacteria
_____f. Watson and Crick
6. Radioactively labeled Phosphorous and Sulfur in
Bacteriophages and saw that the labeled phosphorous was
Present in newly formed bacteriophages following infection
Name_______________________
Miss Badean
Date_________
AP Biology
Molecular Genetics, Viruses,
and Gene Regulation
Exam