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49 Cards in this Set

  • Front
  • Back
1. A growth factor like epidermal growth factor (EGF) will influence gene expression by doing what?
interacting with a receptor that activates the RAS-MAP kinase pathway, leading to phosphorylation of ELK-1
2. alpha-interferon, erythropoietin, prolactin, and growth hormone all act through

A. receptor tyrosine kinases
B. the Jak-STAT pathway
C. the WNT pathway
D. all of the above
E. none of the above
all of the above, receptor tyrosine kinases, the Jak-STAT pathway, the WNT pathway
3. Phosphorylation of which transcription factor is important for its ability to activate transcription?


A. TBP
B. STAT
C. Ras
D. glucocorticoid receptor
E. fos
STAT
4. Epidermal growth factor (EGF) affects cells by


A. magic
B. binding to and activating transcription factor receptors
C. activating the ras-MAP kinase pathway
D. activating a trimeric G protein
E. Ca++ release
activating the ras-MAP kinase pathway
5. The transfer of a phosphate from ATP to a protein can occur on


A serine
B threonine
C tyrosine
D all of the above
E none of the above
all the above, serine, threonine, tyrosine
6. In the RAS-MAPK pathway, ras activates the kinase, raf. raf then phosphorylates mek, mek phosphorylates erk, and erk phosphorylates elk. Which of these might be referred to as the MAP kinase kinase kinase (MAPKKK)?


A raf
B mek
C erk
D elk
raf
7. An example of a “MAP” in the RTK – ras – MAP kinase pathway is


a. myc
b. CDK
c. Rb
d. all of the above
e. none of the above
myc
8. Which of the following describes the covalent modification of a protein to affect its activity through an allosteric transition?


A interaction of cAMP with CAP protein
B binding of substrate in the active site of glyceraldehyde-3-phosphate dehydrogenase
C phopshorylation by a kinase
D quaternary structure
phopshorylation by a kinase
9. G-protein linked receptors are characterized by
A two chains which dimerize
B adenylate cyclase activity in their intracellular domain
C an activated G subunit bound when the signal is not present
D seven membrane-spanning alpha-helical domains
E banana
seven membrane-spanning alpha-helical domains
10. Which of the following is a “2nd messenger”?


A adrenalin
B the G-protein  subunit
C GTP
D calcium
calcium
11. Chromosomes in eukaryotic cells are composed of:


A 100% DNA
B predominantly DNA, with a little RNA present, but no protein lipid, or carbohydrate
C about 50% DNA plus about 50%protein, plus some RNA
D chromosomes in the nucleus are made solely of DNA, whereas the chromosomes are made of RNA when they are in the cytoplasm
E single-stranded DNA complexed with histone proteins
about 50% DNA plus about 50%protein, plus some RNA
12. A nucleosome contains


A histones H2A and H2B
B histones H3 and H4
C 147 base pairs of DNA
D all of the above
all of the above
13. The existence of DNase hypersensitive sites in chromatin reflects


A an absence of nucleosomes on regulatory elements when transcription factors are bound
B active translation of the gene
C the presence of histone H1 and subsequent formation of the 30 nm fiber
D the action of histone deacetylases
an absence of nucleosomes on regulatory elements when transcription factors are bound
14. The nucleosome core particle contains


a. four copies of histone H1
b. 8 different histone proteins
c. four different histone proteins, histones H1, H2, H3 and H4
d. two copies each of histones H1, H2, H3 and H4
e. histones H2A, H2B, H3, and H4
histones H2A, H2B, H3, and H4
15. Repression of transcription is associated with


A DNase insensitivity of the chromatin
B deacetylation of the histones
C binding of transcriptional repressors to promoter and enhancer sequences
D all of the above
all of the above
16. Activation of transcription is associated with which of the following modifications to the chromatin?


a. the nucleosomes become more highly acetylated
b. the DNA becomes phosphorylated
c. the histone H4 is lost from the nucleosome core
d. the promoter protein becomes incorporated into the nucleosome
e. nucleosomes are removed from the splice sites
the nucleosomes become more highly acetylated
17. What is the role of histone acetyltransferases in the activation of gene expression by thyroid hormone?


A histone acetyltransferases bind thyroid hormone and become active as transcription factors
B histone acetyltransferases modify the thyroid hormone so that it can activate transcription
C histone acetyltransferases are recruited to chromatin by the thyroid hormone receptor when it is bound by ligand, and modify chromatin so that transcription can occur
D histone acetyltransferases modify chromatin structure and repress genes, unless thyroid hormone is present, thereby allowing the genes to be activated
histone acetyltransferases modify the thyroid hormone so that it can activate transcription
18. The “10 nm fiber” will not contain


a. DNA
b. histone H1
c. histone H2A
d. histone H3
e. histone H4
histone H1
19. In which case will transcription in vitro be greatest?


a. incubate template with general factors and polymerase
b. incubate template with core histones, then general factors and polymerase
c. incubate template with core histones and histone H1, then general factors and polymerase
d. incubate template with gal4-VP16, general factors and polymerase, then core histones
e. incubate template with gal4-VP16, general factors and polymerase, then core histones and histone H1
incubate template with gal4-VP16, general factors and polymerase, then core histones
20. In an experiment in which the amount of transcription from intact chromatin is being assayed, a histone acetyl transferase might appear to be a


a. transcriptional activator
b. transcriptional repressor
c. RNA polymerase
d. source of nucleotides
e. DNA bending protein
transcriptional activator
21. The nucleosome core particle contains


A) four copies of histone H1
B) 8 different histone proteins
C) four different histone proteins, histones H1, H2, H3 and H4
D) two copies each of histones H1, H2, H3 and H4
E) histones H2A, H2B, H3, and H4
histones H2A, H2B, H3, and H4
22. The appearance of nuclear DNA in the electron microscope gives rise to the descriptive term


A) beads on a string
B) metaphase chromosome
C) double helix
D) coiled coils
E) stuff of life
beads on a string
23. Nucleosomes can contain
A about 200 bp DNA
B an octameric histone core
C H1
D all of the above
D all of the above
24. A nucleosome is
A a body (“-some”) in the nucleus
B a DNA molecule, a chromosome, in the nucleus
C a histone octamer
D 146 bp of DNA wrapped around a histone octamer
E a 30 nm fiber
146 bp of DNA wrapped around a histone octamer
25. Acetylation of histone tails will have what effect on transcription?


A transcription will be increased
B transcription will be decreased
C transcription will not be affected
D the effect is unpredictable
E all of the above will occur at the same time!
transcription will be increased
26. In a transcription assay, the addition of H1 to nucleosomes assembled with core histones on a template will


A further repress transcription
B overcome chromatin repression of transcription
C lead to higher levels of transcription than either core histones or H1 alone
D have no effect on transcription levels
E all of the above will occur at the same time.
further repress transcription
27. In eukaryotes, the product of transcription, which contains a functional open reading frame capable of translation is:


A the codon
B the intron
C the pre-mRNA
D the primary transcript
E the mRNA
C the pre-mRNA
28. RNA processing is carried out by


A factors attached to the polymerase CTD
B factors attracted to the chromatin by transcription factors
C factors found in the cytoplasm, associated with the ribosome
D TAFs
factors attached to the polymerase CTD
29. The factors that carry out RNA processing are found where?
A diffusing freely in the nucleoplasm
B diffusing freely in the cytoplasm
C bound to the nuclear matrix nears nuclear pores
D bound to the DNA at promoters, enhancers and other regulatory sequences
E bound to the RNA polymerase II carboxy-terminal domain
diffusing freely in the nucleoplasm
30. In most eukaryotes, introns begin and end with

A AC…GT
B AC…GU
C GU…AG
D AUG…UGA
E Once upon a time…The end.
GU…AG
31. Which describes an RNA lariat?


A the 3’ terminal nucleotide of the exon is covalently attached to the branchpoint A through a 5’ to 3’ phosphodiester bond
B the 3’ terminal nucleotide of the upstream exon is covalently attached to the 5’ terminal nucleotide of the downstream exon through a 5’ to 3’ phosphodiester bond
C the 5’ terminal G of the intron is attached to the branchpoint A through a 5’ to 3’ phosphodiester bond
D the 5’ terminal G of the intron is attached to the branchpoint A through a 5’ to 2’ phosphodiester bond
E the 3’ terminal G of the intron is attached to the branchpoint A through a 5’ to 2’ phosphodiester bond
the 5’ terminal G of the intron is attached to the branchpoint A through a 5’ to 2’ phosphodiester bond
33. Splicing will occur when the RNA contains which signals?

A a TATA box
B an AAUAAA
C a GU at the 5’ end of the intron and a AG at the 3’ end of the intron
D a stem-loop structure in the 3’ UTR
a GU at the 5’ end of the intron and a AG at the 3’ end of the intron
34. Splicing requires the participation of


a. hnRNA
b. mRNA
c. snRNA
d. rRNA
e. tRNA
snRNA
35. Which of the following are involved in splicing?


A U1
B snRNA
C snurps
D all of the above
E none of the above
all the above
U1
snRNA
snurps
36. Splicing of pre-mRNA is carried out by


A RNA
B protein
C ribonucleoprotein complexes
D the DNA template
E magic
ribonucleoprotein complexes
37. The lariat structure is


A a methyl-G hooked to the 5’ terminal A by a 5’ -> 5’ linkage
B a closed circle of conventional phosphodiester bonds
C a branched nucleotide with phosphate groups on its 5’, 3’, and 2’ carbons
D a branched stretch of RNA with an A at the branch point, and phosphodiester bonds on the A’s 5’, 3’, and 2’ carbons
E a double stranded RNA whose strands are linked together by phosphodiester bonds on the 5’, 3’, and 2’ carbons of all the A’s
a branched stretch of RNA with an A at the branch point, and phosphodiester bonds on the A’s 5’, 3’, and 2’ carbons
38. U1 snRNP recognizes


A the 5’ splice donor
B the 3’ splice acceptor
C the branch point A
D the start codon
E the poly-A signal
the 5’ splice donor
40. Splicing requires


A RNA editing
B U1 snRNA
C CstF (cleavage stimulation factor)
D sxl, tra, and dsx proteins
U1 snRNA
41. The “cap” found on eukaryotic mRNAs is


A bound to the DNA when cAMP levels are high
B a mechanism for response to glucose levels
C a string of G nucleotides added to the 3’ end of the mRNA after transcription
D an A nucleotide added to the 5’ end of the mRNA with a 5’ to 5’ bond
E a G nucleotide added to the 5’ end of the mRNA with a 5’ to 5’ bond
a G nucleotide added to the 5’ end of the mRNA with a 5’ to 5’ bond
42. Polyadenylation will occur most efficiently on messages that contain which of the following sequences?


A. AAUAAA
B. AUUAAA
C. AGUAAA
D. CAUAAA
E. UAUAAA
AAUAAA
43. The polyA tail is added by


A. reverse transcriptase
B. RNA polymerase I
C. RNA polymerase II
D. RNA polymerase III
E. polyA polymerase
polyA polymerase
44. Isoforms are


A different mature mRNAs made from a single gene by alternative splicing
B different proteins made from a single gene by alternative processing of the mRNA
C different proteins derived by phosphorylation and the covalent modification of the mature protein
D different mRNAs derived from a single gene by alternative promoter usage
E plastic containers used in freezers for making iso cubes
different mRNAs derived from a single gene by alternative promoter usage
45. A gene may have more than one version of its exons, and generate various mature mRNA by choosing among them; an extreme example is the Drosophila Dsacm gene. If such a gene has 3 exons, with 2 different versions of exon 1, 10 different versions of exon 2, and 4 versions of exon 3, how many different mRNAs might be made by alternative splicing?

A 1
B 3
C 16
D 40
E 80
80
46. Alternative splicing of a gene with three exons might produce how many proteins?


A 1
B 2
C 3
D 4
E 5
5
47. The Sxl protein acts by


A activating a splice site to control dsx protein isoform
B stimulating a default splicing pathway that leads to male development
C repressing a splice acceptor thereby leading to functional tra protein
D killing flies that are becoming male and thereby stimulating female development
repressing a splice acceptor thereby leading to functional tra protein
48. Sxl and Tra act to control sexual differentiation in the fly by


A controlling transcription
B controlling splicing
C controlling capping
D controlling polyadenylation
E controlling translation
controlling splicing
49. Sex differentiation in Drosophila is controlled by


a. the synthesis of a transcription factor that regulates female-specific genes
b. the activation of a constitutively expressed transcription factor only in females
c. alternative splicing of transcripts produced in both sexes
d. a signal transduction mechanism turns on male-specific differentiation
e. differences in transcription factor stability lead to differences in gene expression in the two sexes
differences in transcription factor stability lead to differences in gene expression in the two sexes
52. U1 snRNP forms hybrids with _____


A branchpoint A
B mRNA
C Shine & Dalgarno sequence
D splice donor
splice donor
53. U2 snRNP forms hybrids with _____


A branchpoint A
B mRNA
C Shine & Dalgarno sequence
D splice donor
A branchpoint A