BIOL 101 -- Exam 3 – September 8, 2006 – Name: ______
DNA Replication
__ 1. Assume DNA replication is NOT semi-conservative. Meselson and Stahl's replication experiment would have shown different results. After growing the bacteria first on heavy 15N, centrifuged results would have shown one band of heavy DNA. If then bacteria were allowed to grow on light 14N, the centrifuged results would have shown:
a) one hybrid band and one light band.
b) one heavy band and one light band.
c) two heavy bands.
d) one hybrid band and one heavy band.
__ 2. In the Watson and Crick model of DNA, the "steps" of the ladder are composed of
a) sugars.
b) a purine and a pyrimidine.
c) two purines.
d) two pyrimidines.
e) a sugar and a phosphate molecule.
__ 3. Which of the following statements about DNA replication is NOT correct?
a) Unwinding of the DNA molecule occurs as hydrogen bonds break.
b) Replication occurs as each base is paired with another exactly like it.
c) The process is known as semiconservative replication because one old strand is conserved in the new molecule.
d) The enzyme that catalyzes DNA replication is DNA polymerase.
e) Complementary base pairs are held together with hydrogen bonds.
__ 4. What is the primer that is required to initiate the synthesis of a new DNA strand?
a) DNA
b) RNA
c) ribosome
d) ligase
e) primase
__ 5. Which enzyme catalyzes the elongation of a DNA strand in the 3' to 5' direction?
a) primase
b) DNA ligase
c) DNA polymerase III
d) helicase
e) none of these
__ 6. The problem of replicating the lagging strand, that is, growing DNA in the 3'--> 5' direction, is solved by DNA through the use of
a) base-pairing
b) replication forks
c) helicases
d) Okazaki fragments
e) topoisomerases
__ 7. What type of bond is used to connect nucleotides within a single strand of DNA?
a) hydrogen
b) ionic
c) covalent
d) sulfhydryl
e) phosphate
__ 8. When does DNA replication occur?
a) mitosis
b) meiosis
c) S phase
d) G1 phase
e) A and B
__ 9. What type of reaction does DNA polymerase catalyze?
a) Oxidative decarboxylation
b) Oxidative phosphorylation
c) Oxidative deamination
d) Dehydration synthesis
e) Phosphotransferase
__ 10. The correct structure of a nucleotide is:
a) Phosphate-5 carbon sugar-nitrogen base
b) Phospholipid-sugar-base
c) Phosphate-sugar-phosphate-sugar
d) Adenine-thymine and guanine-cytosine
e) Base-phosphate-glucose
__ 11. What enzyme removes the RNA primer from the discontinuous strand?
a) primase
b) RNase
c) DNA polymerase I
d) ligase
e) exons
__ 12. Okazaki fragments are short stretches of RNA that will be connected together.
a) True
b) False
__ 13. DNA replication is started at specific DNA sequences referred to as ____ sites.
a) ori
b) Shine-Delgaro
c) promoter
d) Jacobs box
e) TATA box
__ 14. Which enzyme has the ability to separate double stranded DNA into single strands?
a) ligase
b) helicase
c) gyrase
d) polymerase
e) primase
__ 15. What is the relationship among DNA, a gene and a chromosome?
a) A chromosome contains hundreds of genes which are composed of protein.
b) A chromosome contains hundreds of genes which are composed of DNA.
c) A gene contains hundreds of chromosomes which are composed of protein.
d) A gene is composed of DNA, but there is no relationship to a chromosome.
e) A gene contains hundreds of chromosomes which are composed of DNA.
Transcription, Translation & RNA processing
__ 16. If a bacterial protein has 30 amino acids, how many nucleotides are needed to code for it?
a) 30
b) 60
c) 90
d) 120
e) 600
__ 17. The sequence of nitrogenous bases on one strand of DNA may determine the sequence of:
a) Fatty acids in a fat molecule
b) Amino acids in a protein molecule
c) Sugars in a polysaccharide molecule
d) All of the above choices are correct
e) Bases in a protein molecule
__ 18. Which of these is found in RNA but not in DNA?
a) Adenine
b) Uracil
c) Thymine
d) Phosphate groups
e) Deoxyribose sugar
__ 19. The number of consecutive mRNA bases needed to specify an amino acid is:
a) 3
b) 4
c) 20
d) 64
e) A variable number
__ 20. The process of copying genetic information from DNA to RNA is called:
a) Translation
b) Transformation
c) Replication
d) Transcription
e) Polymerization
__ 21. Which of the following molecules functions to transfer information from the nucleus to the cytoplasm?
a) DNA
b) mRNA
c) tRNA
d) Proteins
e) Lipids
__ 22. A transcription start signal is called
a) an initiation codon.
b) a promoter.
c) an origin.
d) a start site.
e) a nonsense codon.
__ 23. If a tRNA molecule specialized for transfer of the amino acid valine has the anticodon CAG, with what codon will it couple?
a) GAC
b) GTC
c) TUG
d) GUC
e) CAG
__ 24. Joins up with amino acids
a) ribosomal RNA
b) DNA
c) messenger RNA
d) transfer RNA
e) RNA polymerase
__ 25. Contains codons
a) ribosomal RNA
b) DNA
c) messenger RNA
d) transfer RNA
e) RNA polymerase
__ 26. Makes RNA molecules in the nucleus
a) ribosomal RNA
b) DNA
c) messenger RNA
d) transfer RNA
e) RNA polymerase
__ 27. Occurs at ribosomes
a) Transcription
b) Translation
c) Replication
d) Cytokinesis
e) Both transcription and translation
__ 28. The site of protein synthesis is the:
a) Endoplasmic reticulum
b) Nucleus
c) Nucleolus
d) Ribosome
e) Eukaryotic chromosome
__ 29. Anticodon-codon pairing
a) Transcription
b) Translation
c) Replication
d) Cytokinesis
e) Both transcription and translation
__ 30. A part of a mRNA molecule with the following sequence (5¨-CCG ACG-3¨) is being translated by a ribosome. The following activated tRNA molecules are available. Two of them can correctly match the mRNA so that a dipeptide can form. The dipeptide that will form will be
tRNA anticodon Amino acid
GGC proline
CGU alanine
UGC threonine
CCG glycine
ACG cysteine
CGG alanine
a) cysteine-alanine
b) proline-threonine
c) glycine-cysteine
d) alanine-alanine
e) threonine-glycine
__ 31. Each new amino acid is attached to the growing chain during translation by:
a) an ionic bond
b) a physical bond
c) hydrogen bonds
d) an RNA bond
e) a peptide bond
__ 32. Ribosomes are a collection of
a) small proteins that function in translation.
b) proteins and small RNAs that function in translation.
c) proteins and tRNAs that function in transcription.
d) proteins and mRNAs that function in translation.
e) mRNAs and tRNAs that function in translation.
__ 33. Which of the following is/are true concerning introns?
a) Introns are sections of nucleotides found on a mRNA transcript.
b) RNA splicing usually removes introns from a mRNA molecule.
c) Introns can function to regulate gene expression.
d) The sequence of nucleotides found in introns are not known to represent anything usable by the cell.
e) Introns are removed by spliceosomes.
__ 34. During the elongation of a polypeptide chain, ______occurs when the mRNA moves to the next site on the ribosome to read the next codon.
a) translocation
b) transcription
c) transformation
d) translation
e) transference
__ 35. Transcription of a part of a DNA molecule with a nucleotide sequence of A-A-A-C-A-A-C-T-T results in a mRNA molecule with the complementary sequence of
a) G-G-G-A-G-A-A-C-C.
b) U-U-U-G-U-U-G-A-A.
c) T-T-T-G-A-A-G-C-C.
d) C-C-C-A-C-C-T-C-C.
e) none of the choices are correct.
__ 36. What part of the RNA polymerase molecule recognizes the promoter?
a) gamma factor
b) alpha factor
c) apoenzyme
d) sigma factor
e) beta factor
__ 37. For translation to take place, which of the following would NOT be required to be present?
a) tRNA-amino acid complex.
b) DNA.
c) mRNA.
d) rRNA.
e) ribosome.
__ 38. The correct sequence of events in the production of a polypeptide is
a) initiation, termination, elongation.
b) elongation, termination, initiation.
c) termination, elongation, initiation.
d) elongation, initiation, termination.
e) initiation, elongation, termination.
__ 39. In which directions does transcription occur?
a) in the 3’ to 5’ direction
b) in the 5’ to 3’ direction
c) in the 3’ to 3’ direction
d) in the 5’ to 5’ direction
e) all of these
__ 40. The genetic code is said to be degenerate. What does this indicate?
a) A single code is used by all species.
b) The codons overlap.
c) The code has punctuation.
d) The code does not have punctuation.
e) There are multiple codons for some amino acids.
__ 41. Uracil pairs with:
a) Thymine
b) Adenine
c) Guanine
d) Cytosine
e) Uracil
__ 42. What mRNA carries from the nucleus is:
a) Enzymes
b) Ribosomes
c) Information
d) Amino acids
e) tRNA
__ 43. After introns are removed, the ___ are joined together to form functional mRNA.
a) axons
b) neutrons
c) exons
d) mesons
e) ori sites
__ 44. rRNA has an anticodon loop at one end of the molecule and an amino acid acceptor stem at the other end.
a) true
b) false
__ 45. What is added to the 5’ end of an RNA molecule during processing?
a) UAG
b) poly-A
c) poly-T
d) a cap
e) none of these
Mitosis, Meiosis & Cytokinesis
__ 46. A bacterial cell splits into 2 new cells by:
a) Duplication
b) Forming a cell plate
c) Forming a cell furrow
d) Mitosis
e) Binary fission
__ 47. Diploid cells of the fruit fly Drosophila have 10 chromosomes. How many chromosomes does a Drosophila gamete have?
a) one
b) two
c) five
d) ten
e) twenty
__ 48. Human body cell nuclei contain:
a) 46 pairs of chromosomes
b) 44 pairs of chromosomes
c) 23 unpaired chromosomes
d) 22 pairs of chromosomes
e) 23 pairs of chromosomes
__ 49. During the "S" portion of the cell cycle, what is the cell doing?
a) resting
b) general cell metabolism
c) synthesizing DNA
d) making a spindle
e) undergoing differentiation
__ 50. Which of these sequences correctly describes the cell cycle?
a) ® G1 ® G2 ® S ® prophase ® metaphase ® anaphase ® telophase ®
b) ® S ® G2 ® prophase ® metaphase ® anaphase ® telophase ® G1 ®
c) ® G1 ® S ® G2 ® prophase ® anaphase ® metaphase ® telophase ®
d) ® prophase ® metaphase ® telophase ® anaphase ® G1 ®S ® G2 ®
e) ® G1 ® S ® G2 ® metaphase ® prophase ® anaphase ® telophase ®
__ 51. When does chromosome replication occur in a eukaryotic cell?
a) Prophase
b) Metaphase
c) Anaphase
d) Interphase
e) Telophase
__ 52. The longest period of a cell's life cycle is:
a) Prophase
b) Telophase
c) Interphase
d) Anaphase
e) Metaphase
__ 53. During mitotic anaphase, chromatids migrate
a) from the poles of the cell toward the metaphase plate.
b) from the metaphase plate toward the poles.
c) toward the nuclear envelope.
d) along with their sister chromatids toward one pole.
e) along with the other member of the homologous pair toward the metaphase plate.
__ 54. The microtubules of the mitotic spindle attach to a specialized structure in the centromere region of each chromosome, called the
a) kinetochore.
b) nucleosomes.
c) equatorial plate.
d) nucleotide.
e) centrosome.
__ 55. If a liver cell of an animal has 24 chromosomes, then the sperm cells of this animal would also have 24 chromosomes.
a) True
b) False
__ 56. Cytokinesis refers to the division of the:
a) Cell
b) Nucleus
c) Mitochondria
d) Centrioles
e) Chromosomes
__ 57. Sister chromatids are:
a) Duplicate chromosomes held together by a common centromere
b) Specialized gamete-forming cells
c) Non-functional chromosomes
d) Homologous pairs of chromosomes
e) Different in their genetic content
__ 58. Mitosis in humans usually results in the formation of:
a) 2 diploid cells
b) 4 diploid cells
c) 2 haploid cells
d) 4 haploid cells
e) Sperm or egg cells
__ 59. During which stage of mitosis do chromosomes line up at the equator of the spindle apparatus?
a) Prophase
b) Metaphase
c) Anaphase
d) Telophase
e) The chromosomes do not line up at all
__ 60. Which of the following does not occur during prophase?
a) The nuclear membrane disintegrates
b) Nucleoli break up
c) The spindle apparatus forms
d) The chromosomes condense
e) DNA replicates
__ 61. Nuclear envelope reforms.
a) Metaphase
b) Prophase
c) Telophase
d) Anaphase
e) None of the these
__ 62. Spindle apparatus formation occurs.
a) Metaphase
b) Prophase
c) Telophase
d) Anaphase
e) None of the these
__ 63. Cytokinesis occurs.
a) Metaphase
b) Prophase
c) Telophase
d) Anaphase
e) None of the these
__ 64. Sexual reproduction by necessity involves which two processes?
a) Meiosis and fertilization
b) Mutation and translocation
c) Nondisjunction and pleiotropy
d) Mitosis and fertilization
e) Differentiation and specialization
__ 65. Meiosis results in the production of:
a) Diploid cells with no homologous chromosomes
b) Diploid cells with homologous chromosomes
c) Haploid cells with no homologous chromosomes
d) Haploid cells with homologous chromosomes
e) None of the above choices is correct
__ 66. During anaphase of meiosis I, what segregates?
a) Sister chromatids
b) The spindle
c) Homologous chromosomes
d) Non-allelic genes
e) The nucleolus
__ 67. Reciprocal exchange of genetic material between similar chromosomes is called: