Biochemistry MCQ Quiz Hub

1.  Which of the following species lack a 'classical' histone H1?
Saccharomyces cerevisiae
Strongylocentrotus purpuratus
Xenopus laevis
Arabidopsis thaliana

2. Which of the following is correct?
Replication starts at a single origin
Replication is bidirectional
Replication is semi conservative
All of the above

3. Which of the following are short nucleotides strands made by DNA polymerase working in the opposite direction of the replication fork?
Leading strands
Okazaki fragments
Primers
Lagging strand

4. Which of these drugs bind to DNA and cuts it, producing hydroxyl radicals?
Bleomycin
Erythromycin
Tunicamycin
All of these

5. Replication in E. coli is initiated by the generation of short RNA primers using
RNA polymerase
primase
reverse transcriptase
both (a) and (b)

6. DNA replication results in
two completely new DNA molecules
two DNA molecules such that each one contains a strand of the original
one new DNA molecules 1 old molecule
one new molecule of RNA

7. Which enzyme catalyzes the elongation of DNA molecules?
DNA polymerase
Helicase
DNA ligase
Primase

8. What is the IUPAC code for an A, C, T ambiguity in a nucleic acid sequence?
B
H
S
None of these

9. There is a single origin for DNA replication in bacteria. How many origins of replication are found in the much larger genomes of eukaryotes such as mammals?
One
About 100
Thousands and tens of thousands
none of these

10. Automated DNA sequencing uses the chain termination method
but with an oligonucleotide primer labeled with a fluorescent dye
but with a polynucleotide primer labeled with a fluorescent dye
with no primer
either (b) or c

11. Okazaki fragments occur on the __________ and are bonded together by _________
Leading strand, polymerase
mRNA, anticodons
Lagging strand, ligase
tRNA, polymerase

12. The RNA primers used to initiate replication in E. coli
result in Okazaki fragments on leading strand
are removed by Pol I
are joined together by DNA ligase
are removed by helicase + ATP

13. An enzyme that recognizes foreign DNA, and results in a cut in that DNA is called
transposase
helicase
reverse transcriptase
restriction endonuclease5

14. Which of the following is an active site on its single polypeptide chain for DNA Polymerase I?
5' → 3' polymerase
3' → 5' exonuclease
5' → 3' exonuclease
all of the above

15. Which of the following is not a structural motif in DNA binding proteins?
bZIP
helix-turn-helix
TFIID
. zinc finger

16. DNA with a G-C content of 50% will melt at approximately
60°C
70°C
90°C
100°C

17. Who's X-ray work aided Watson and Crick in their discovery of the double helix?
W.H. Bragg
R. Franklin
L. Pauling
Leaderberg

18. DNA replication in eukaryotes occurs only in
G1 phase
S phase
G2 phase
M phase

19. Which polymerase is active in DNA repairing
Polymerase I
Polymerase II
Polymerase III
none of these

20. For the DNA replication in eukaryotes, the cell cycle consists of
G1, G2 and M phases
S, G2 and M phases
G1,S, G2 and M phases
G2 and M phases

21. Which of the following in DNA replication and transcription are common?
incorporation of deoxynucleotides
utilization the same enzyme
synthesis in the 5'-3' direction
none of the above

22. An important difference between eukaryotic and prokaryotic DNA replication is
eukaryotic DNA polymerases are faster
more DNA polymerases are found in eukaryotes
multiple origins of replication in eukaryotes
RNA primers are not required in eukaryotes

23. In DNA, nucleotides are covalently joined together by
3', 5' phosphodiester bonds to form a repetitive sugar-phosphate chain
2', 5' phosphodiester bonds to form a repetitive sugar-phosphate chain
2', 3' phosphodiester bonds to form a repetitive sugar-phosphate chain
3', 4' phosphodiester bonds to form a repetitive sugar-phosphate chain

24. What is the name given to the points at which a DNA helix is unwound and new strands develop?
Replication origins
Replication forks
Leading strands
Okazaki fragments

25. The DNA is negatively super coiled, complexes to histone,
HU
HSP-1
H-NS
All of these

26. During conventional transformation experiments E. coli cells and plasmid DNA interacts in an environment of
high temperature and Ca++
low temperature and Ca++
high temperature and Mg++
low temperature and Mg++

27. What is the exact name of the classical Watson-Crick double helix DNA?
A-DNA
B-DNA
Z-DNA
X-DNA

28. The site on a bacterial chromosome that marks the initiation point for chromosome replication is called
Ori
a promoter
Pro
an initiation codon

29. The B-DNA structure found in solution is a
left-handed double helix of antiparallel chains (10 bp/turn)
right-handed double helix of antiparallel chains (∼10 bp/turn)
left-handed zig-zag helix of antiparallel chains (10 bp/turn)
right-handed double helix of parallel chains (∼10 bp/turn)

30. Which will require a higher temperature to denature?
DNA with a high G-C content
DNA with a high A-T content
RNA with a high G-C content
RNA with a high A-T content

31. In an agarose gel, DNA is moving from
cathode to anode
left to right
anode to cathode
A to B

32. TM refers to the temperature at which
membranes are 50% fluid
50% of a DNA molecule is denatured
50% of a protein molecules are denatured
all of the above

33. DNA segments capable of moving from one place in the genome to another is known as
transposons
retrovirus
introns
moving elements

34. What does ligase do during replication of DNA?
Synthesizes the lagging strand
Makes copies of mRNA from DNA
Joins nicks in DNA strands
Digests mRNA when it is no longer needed

35. Proteins which help to open the double helix for DNA synthesis are
DNA helicases
single stranded binding proteins
ligase
DNA topoisomerase

36. First evident that DNA is genetic material comes from the experiment of Griffith is
transduction
transformation
replication
translation

37. An RNA primer is synthesized by
DNA helicases
ligase
DNA topoisomerase
primase

38. Which of these restriction enzymes produce blunt ends?
SaII
EcoRV
XhoI
HindIII

39. The RP13 gene of chromosome 17 codes for a protein __________ .
involved in glucose transport
that is a component of hair and nails
involved in eye development
involved in the determination of personality

40. Isoschizomers recognize
same recognition sequence but different recognition site
same recognition site and recognition sequence
same recognition site and different recognition sequence
different recognition site and different recognition sequence

41. Restriction enzymes are named for
the person who discovered
the bacterium they are derived from
the viral DNA that they attack
none of the above

42. Which of these genes codes for a protein that plays a role in white blood cell function?
DCP1
MPO
GLUT4
RP13

43. When populations are small, gene frequencies can change from generation to generation and some alleles may become fixed in a population. This is called __________ .
assortative mating
inbreeding
heterosis
genetic drift

44. Which of the following is correct in terms of determination of location of genetic traits?
Known protein coding sequences are too far apart to allow linkage determination for most new genes
Restriction sites allow DNAs to be digested
Protein-coding genes are always associated with a restriction pattern
None of the above

45. n gel electrophoresis, DNA molecules migrate from __________ to __________ ends of the gel.
negative ... positive
basic ... acidic
long ... short
positive to negative

46. Restriction enzymes
protect bacteria from viral infection
cut DNA in a staggered fashion
cut DNAs producing a blunt end
all of the above

47. First discovered, Type II restriction endonuclease was
Hinf I
Eco K
Hind II
EcoRI

48. Which of the following techniques can be used to determine the defective gene and for developing cancer?
Western blot
Southern blot
Northern blot
Eastern blot

49. The transfer of antibiotic-resistant genes from genetically engineered bacteria to disease-causing bacteria __________ .
would be of no concern if it occurred.
has occurred
can never occur
seems unlikely

50. Both DNA gel electrophoresis and SDS-PAGE of proteins are similar because
in both cases molecules migrate to the anode
both techniques rely on a constant charge to mass ratio
both techniques utilize the sieving properties of gels
all of the above

51. Some genetic diseases cannot be diagnosed by changes in restriction sites. Some of these can be detected by allele-specific oligonucleotide probes. These are
copies of the gene with an altered sequence so that a restriction site is inserted
mutagenized copies of a gene
short sequences that will hybridize only to a specific base sequence
PCR-amplified variable numbers of tandem repeats (VNTRs)

52. In order to insert a foreign gene into a plasmid, both must __________
have identical DNA sequences
originate from the same type of cell
be cut by the same restriction enzyme
be of the same length

53. Which of the following genetic diseases would be amenable to genetic engineering?
Down's syndrome
Muscular dystrophy
Cystic fibrosis
Cri du Chat

54. X-rays cause
the formation of thymine dimers
ionization of water in the cell
heat
none of the above

55. The order for the construction of a cDNA fragment from mRNA is to
bind oligo-dT, treat with reverse transcriptase, digest with RNase, add G residues to the 3' end, bind oligo-dC, treat with DNA polymerase
treat with reverse transcriptase, digest with RNase, add G residues to the 3' end, bind oligo-dC, treat with DNA polymerase and bind oligo-dT
digest with RNase, add G residues to the 3' end, treat with reverse transcriptase, add G residues to the 3' end and treat with DNA polymerase
bind oligo-dC, treat with reverse transcriptase, digest with RNase, add G residues to the 3' end, bind oligo-dT and treat with DNA polymerase

56. The TP53 gene of chromosome 17 codes for a protein __________ .
that plays a role in the digestive process
involved in glucose transport
involved in the regulation of the cell cycle
that is like a white blood cell protein

57. Why is golden rice pale yellow in color?
It is rich in chlorophyll a.
It is rich in beta-carotene.
It is rich in chlorophyll b.
It is rich in phycobilins.

58. Which type of restriction enzymes do not usually require ATP?
Type I
Type II
Type III
Type IV

59. An example of a restriction fragment length polymorphism is
an Eco RI cuts DNA at a different sequence than Hind III
different length fragments of DNA resulting from loss or gain of a restriction site
cystic fibrosis results from a three base deletion in most cases but in other cases, other mutations are involved
all of the above

60. Knockout mice are created by
mutagenizing a mouse and selecting for mutant offspring
creating a chimera by fusing cells from two different cell lines
infecting the mouse with a retrovirus
transfecting embryonic stem cells with an altered gene sequence

61. A plasmid
is a circular DNA molecule
always contains an origin of replication
usually contains one or more restriction sites
all of the above

62. Under which of the following conditions would population gene frequencies remain the same?
Selection for homozygotes
Small population size
Active migration between groups
Random mating

63. Plant transformation can be obtained by
combining plant and animal cells in culture
shooting DNA into plant cells with a gun
using the E. coli bacterium to infect plant roots
infecting plants with a tobacco mosaic virus

64. An expression vector
always contains an origin of replication
usually contains a gene that confers antibiotic resistance to the bacterial host
always contains DNA segments for the regulation of mRNA production
all of the above

65. he unpaired nucleotides produced by the action of restriction enzymes are referred to have
sticky ends
single strands
restriction fragments
ligases

66. Which of the following is not true of small inbreeding populations?
They tend to loose genetic diversity
There is an increased incidence of recessive diseases
Alleles may become fixed
Mutation is increased

67. Which of these genes codes for a protein that plays a role in growth?
DCP1
SCLC6A4
KRTHA1
GH1

68. Which of the following pair will produce complementary sticky ends?
Eco RI & MspI
Msp I & HPA II
Sau 3A & Bam HI
Mbo I & Sau 3A

69. A human cDNA library
contains DNA for specific human proteins
contains DNA for virtually all of the human proteins in vectors
cannot be used to obtain human genes because it would be radioactive
none of the above

70. What enzyme forms covalent bonds between restriction fragments?.
DNA primase
DNA helicase
DNA polymerase
DNA ligase