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Last Updated
2/28/06
General Essay Type Questions
1) Describe the lac operon, and how it works
to regulate the level of b-galactosidase,
in E. coli. Don't forget to include catabolite repression.
2) Describe how the tryptophan operon of E. coli
functions (Include the attenuator).
3) What are the significance of cis-acting and trans-acting
factors in transcription?
4) Describe how pre-mRNA becomes mRNA.
5) What are post-transcriptional and post-translational
controls?
Multiple Choice
Questions
1) The trp attenuator... A) is a DNA-RNA
hybrid. B) is a pallendrome. C) is regulated by CAP.
D) is a direct repeat. E) binds cAMP.
2) The lac operon is induced by... A) allolactose. B) galactose. C) corepressor. D) glucose. E) X-gal. F) cAMP.
3) Attenuators ... A) stop initiation of transcription. B) stop termination of transcription. C) stop elongation of transcription. D) stop initiation of translation.
4) Catabolite repression of the lac operon ... A) requires cAMP levels to be low. B) requires lactose levels to be low. C) requires glucose levels to be low. D) requires cAMP to bind CAP.
5) The trp operon ... A) uses tryptophan as an inducer. B) uses cAMP as an inducer. C) regulates the level of enzymes needed to make tryptophan. D) binds CAP.
6) b-galactosidase ... A) is a metabolite of lactose. B) converts lactose to glucose and galactose. C) is a metabolite of glucose. D) converts allolactose to sucrose.
7) Sequences downstream of the translation start site in most eukaryotes... A) include the stop codon. B) include the transcription start site. C) include the GC Box. D) are labeled with negative numbers. E) include the TATA Box region.
8) Pick the ONE true statement. A) snRNPs are found in polysomes. B) Replication of DNA occurs in the 3' to 5' direction. C) All hnRNA is processed and transported out of the nucleus. D) mRNAs can be translationally inactive.
9) Which ONE of the following statements is NOT true? A) hnRNA can have introns. B) 5S RNA is found in both prokaryotic and eukaryotic ribosomes. C) The degeneracy of the genetic code is due mostly to wobble. D) The CCAAT box is "downstream" of the transcription initiation site. E) Addition of a Poly(A) tail is a post-transcriptional event.
10) Which sequence is a palindrome when double stranded? A) CCTATGGATA B) ATAGGGGATA C) ACTATGGATA D) CCTATATAGG E) CCTATCCTAT
11) Sequences upstream of the transcription start site in most genes transcribed by RNA pol II... A) include the poly A addition sequence. B) include introns. C) include the GC box. D) are labeled with positive numbers. E) include the polypeptide coding region. F) do not include the CAAT box.
12) Most Eukaryotic mRNAs have a... A) 3' cap of 7mCppp. B) 3' cap of 7mGpp. C) 5' cap of 7mCppp. D) 5' cap of 7mGpp. E) 3' cap of 7mGppp. F) 3' cap of 7mCpp. G) 5' cap of 7mGppp. H) 5' cap of 7mCpp.
13) Which of the following is NOT TRUE? A) Viral DNA replicates with the bacterial chromosome during lysogeny. A) The lytic phase of the lambda infection produces new viruses. C) Lambda DNA in an E. coli chromosome is called an episome. D) Viruses self asemble when their proteins and nucleic acids are mixed together.
14) Which mutant DECREASES transcription of the Lac operon? A) The repressor fails to bind the operator. B) The repressor gene fails to make the repressor. C) CAP by itself binds RNApol. D) The operator is missing. E) The repressor fails to bind the inducer.
15) Which ONE of the following is NOT true? A) The E. coli sex pillus is hollow. B) F+ E. coli make pilli. C) All functional plasmids have an ori. D) Each eukaryotic chromosome has ONE ori.
16) Lambda genes ... A) are eukaryotic. B) can be either prokaryotic or eukaryotic. C) are prokaryotic. D) are neither prokaryotic nor eukaryotic.
17) Virus genes... A) are prokaryotic. B) can be either prokaryotic or eukaryotic. C) are eukaryotic. D) are neither prokaryotic nor eukaryotic.
18) Cotranslational transcription... A) is nuclear. B) is neither prokaryotic nor nuclear. C) is prokaryotic. D) can be either prokaryotic or nuclear.
19) Polycistronic messenger RNAs... A) can be either prokaryotic or eukaryotic. B) are prokaryotic. C) are neither prokaryotic nor eukaryotic. D) are eukaryotic.
True/False
Questions
A) The half-life of RNA never changes. B)
The CAAT box is found in introns. C) Operons are found in
animals. D) Most eukaryotic mRNA's have "caps" and "tails".
E) Transcription factors are proteins. F) Introns are
found in mature mRNA. G) Lambda assembles spontaneously when
its proteins and DNA are mixed together. H) snRNPs are found
in polysomes. I) All hnRNA is processed and transported out of
the nucleus. J) CAP-cAMP is cis acting.
Matching
I) Match the term on the right with the best
description on the left. All RNA sequences below are written as DNA
sequences (Answers may be used more than once).
___1) Needed for RNA
splicing................................................. A) GC
Box
___2) Primary transcript for RNA pol II
................................... B) Intron
___3) Poly A addition sequence
................................................ C) ATG
___4) Intervening sequence
....................................................... D) Exon
___5) Added to the 5' end of RNA after transcription ................
E) CAAT box
___6) Part of a split gene which codes for a polypeptide ...........
F) AATAAA
___7) Spliced out region of mRNA
........................................... G) hnRNA
___8) 100-200 AMPs on 3' end of
RNA.................................... H) snRNP
....................................................................................................
I) Cap
....................................................................................................
J) Exonuclease
....................................................................................................
K) Endonuclease
....................................................................................................
L) Tail
....................................................................................................
M) GTG
II) Match the term on the left with the best term on the right. All RNA sequences below are written as DNA sequences (Answers may be used more than once).
___ 1) Adds 3'
tail........................................................................................
A) Coding region
___ 2) Shows active
translation....................................................................
B) Exon
___ 3) b-galactosidase produces this
product.............................................. C) Reverse
transcriptase
___ 4) Open reading
frame..........................................................................
D) Poly A polymerase
___ 5) A sequence ensuring the proper initiation site of
transcription.......... E) 7mCppp
___ 6) The Lac repressor binds this
sequence.............................................. F) 7mGppp
___ 7) hnRNA sequence missing in
mRNA................................................. G)
Allolactose
___ 8) Binds catabolite activating
protein..................................................... H)
Tryptophan
___ 9) Part of the eukaryotic core
promoter................................................. I) DNA
ligase
___10) Inducer of the Lac
operon................................................................
J) TATA box
___11) Makes phosphodiester
bonds.......................................................... K)
CCAAT box
.....................................................................................................................
L) Intron
.....................................................................................................................
M) cAMP
.....................................................................................................................
N) Lactose
.....................................................................................................................
O) Polysome
.....................................................................................................................
P) Operator
.....................................................................................................................
Q) Glucose
Other
Questions
1) Put an X in the box under transcriptional
control if an event is transcriptional, put an X in the box under
translational control if an event is translational, put an X in the
box under post-trancriptional control if the event is
post-transcriptional, and put an X in the box under
post-translational control if the event is post-translational (Each
event can have more than one answer - disregard the mitochondria
and plastids of eukaryotes for this problem).
.............................................................................................................
post-tran- .......... post-trans-
Event ........................................ transcriptional ......
translational ........ scriptional ............ lational
Protein processing ......................... ______ ..............
______ .............. ______ .............. ______
Transcription factors bind DNA .... ______ .............. ______
.............. ______ .............. ______
Polysome formation ...................... ______ ..............
______ .............. ______ .............. ______
RNA processing ............................ ______ ..............
______ .............. ______ .............. ______
2) (fill-in the blank) In the 1950's ______________________________________ studied the Lac operon.
3) Put an X in the box under eukaryotic if an event is eukaryotic, put an X in the box under prokaryotic if an event is prokaryotic, put an X in the box under Eukaryotic & Prokaryotic if it is both. (disregard the mitochondria and plastids of eukaryotes for this problem).
Event or structure ............................. Eukaryotic ...................... Prokaryotic ........... Eukaryotic & Prokaryotic
A- Polycistronic mRNA ..................... ______
............................ ______ ............................
______
B- 70s ribosomes ............................... ______
............................ ______ ............................
______
C- one ori per chromosome ................ ______
............................ ______ ............................
______
D- RNA processing ............................ ______
............................ ______ ............................
______
E- hnRNA ........................................... ______
............................ ______ ............................
______
F- snRNA ........................................... ______
............................ ______ ............................
______
G- Co-translational transcription ......... ______
............................ ______ ............................
______
H- Viruses ........................................... ______
............................ ______ ............................
______
4) Name one post transcriptional event which is NOT translational or post translational. ____________________________________
5) Name one post transcriptional event which is also post translational. ____________________________________________________
6) RNA attached to Protein is called a ______________________________________.
7) mRNA attached to ribosomes is called a ______________________________________.
8) An Hfr strain of E. coli is mixed with an F- strain of E. coli and "mating" is interrupted every two minutes. The F- bacteria are A- B- C- D- E- and the Hfr bacteria are A+ B+ C+ D+ E+. After "mating", the bacteria are plated on media Hfr bacteria can not grow on. The phenotypes are named for the genotypes and the following table was produced.
Phenotype Time of first appearance
of the phenotype (min.)
A+ ............................................
82
B+ ............................................ 32
C+ ............................................ 54
D+ ............................................ 62
E+ ............................................
48
Draw a genetic map of the chromosome showing the distance between adjacent genes.
9) An Hfr strain of E. coli is mixed with an F- strain of E. coli and "mating" is interrupted every two minutes. The F- bacteria are a- Adh- Sod- D- Q- and the Hfr bacteria are a+ Adh+ Sod+ D+ Q+. After "mating", the bacteria are plated on media Hfr bacteria can not grow on. The phenotypes are named for the genotypes and the following table was produced.
Phenotype ............. Time of
first appearance of the phenotype (min.)
a+
.......................................................... 21
Adh+
...................................................... 93
Sod+
...................................................... 48
D+
......................................................... 56
Q+
.........................................................
70
Draw a genetic map of the chromosomeshowing
the distance between adjacent genes.
==============================================================
General Essay Type
ANSWERS
1 through 5) There are many diiferent ways these could be
aswered. The answers should be accurate, and show that you understand
the concept.
Multiple Choice
ANSWERS
1) B) is a pallendrome
2)
A) allolactose
3)
C) stop elongation of
transcription. (premature
termination) 4)
A) requires cAMP levels to be low
5)
C) regulates the level of enzymes
needed to make tryptophan 6)
B) converts lactose to glucose
and galactose 7)
A) include the stop codon
8)
D) mRNAs can be translationally
inactive 9) False
statement D) The CCAAT box is
"downstream" of the transcription initiation site
10)
D) CCTATATAGG
11)
C) include the GC box
12)
G) 5' cap of 7mGppp
13) False statement
C) Lambda
DNA in an E. coli chromosome is called an episome
14)
E) The repressor fails to bind
the inducer. 15) The ONE
False statement is... D)
Each eukaryotic chromosome has ONE ori.
16)
C) are prokaryotic.
17)
B) can be...
18)
C) is prokaryotic.
19)
B) are prokaryotic.
True/False
ANSWERS [Only the true
statements are written below]
D) Most eukaryotic mRNA's have "caps" and "tails".
E) Transcription factors
are proteins. G) Lambda assembles
spontaneously when its proteins and DNA are mixed together.
Matching ANSWERS
REDO
I -- 1) G or H
2) G
3) F
4)
B 5) I
6) D
7) B
8) L
I I-- 1) D 2) O 3) Q 4) A 5) J 6) P 7) L 8) M 9) J 10) G 11) D or I
Other Questions
ANSWERS
1) Protein processing
....................post-transcriptional
& post-translational
Transcription factors bind DNA
....transcriptional
Polysome formation
......................translational
&
post-transcriptional
RNA processing
............................post-transcriptional
2) In the 1950's Jacob & Monod studied the Lac operon.
3) Polycistronic mRNA
................Prokaryotic
70s ribosomes
...............................Prokaryotic
one ori per chromosome
................Prokaryotic
RNA processing
............................Eukaryotic
hnRNA
..........................................Eukaryotic
snRNA
..........................................Eukaryotic
Co-translational transcription
........Prokaryotic
Viruses
..........................................Eukaryotic
&
Prokaryotic
4) Name one post transcriptional event which is NOT translational or post translational. Two answers: Removal of introns from hnRNA and transport of RNA from the nucleus.
5) Name one post transcriptional event which is also post translational. Two answers: Phosphorylation of proteins and proteolysis.
6) RNA attached to Protein is called a Ribonucleoprotein.
7) mRNA attached to ribosomes is called a Polysome (or Polyribosome, or Polysomal RNA).
8) A genetic map of the chromosome showing the distance between adjacent genes.
9) A genetic map of the chromosome showing the distance between adjacent genes.
