Download BI 200 - Exam #4

BI 200 - Exam #4
Fall 2003
Name
Lab Section
Disclaimer
Consider each question, and answer each in the appropriate format (e.g., multiple choice).
You may qualify your answer if you have reservations. If your comments have merit,
you may receive partial or full credit.
Multiple Choice - 2 points each
1. Which statement describes the chromosomal content of a typical bacterium?
a. Two copies of a single double-stranded, circular DNA molecule.
b. Two copies of a single double-stranded, circular RNA molecule.
c. One copy of a single double-stranded, circular DNA molecule.
d. Two copies of multiple double-stranded, linear DNA molecules.
2. The inability to ferment lactose is an example of
a. a visible phenotypic marker
b. a differential phenotypic marker
c. a selectable phenotypic marker
d. a heterozygote
3. Resistance to the antibiotic penicillin is an example of
a. a visible phenotypic marker
b. a differential phenotypic marker
c. a selectable phenotypic marker
d. a homozygote
4. A mutant unable to synthesize the amino acid tryptophan is an example of
a. wild type
b. a prototroph
c. an autotroph
d. an auxotroph
5. Which of the following would be the correctly expressed phenotypic and genotypic
designation for such a mutant?
a. TRP -; trpA
b. Trp+; trpA
c. Trp-; trpA
d. Lac +; TrpA
6. Which of the following is not a means of gene exchange among bacteria?
a. transcription
b. transformation
c. conjugation
d. transduction
7. Genes on plasmids may be responsible for all of the following except:
a. expression of a virulence factor
b. synthesis of ribosome protein
c. synthesis of pili
d. transfer of drug resistance
e. degradation of pollutants
8. In conjugation genes on plasmids are transferred in matings between:
a. two F- strains
b. F+ and F- cells
c. two F+ strains
d. a and b
e. b and c
9. Which of the following is not true about transformation?
a. Viruses are not involved.
b. The process is not sensitive to the enzyme DNase.
c. DNA can be transferred between species.
d. The donor cell must be lysed before transfer can take place.
10. A gene with 90 codons would have _________ base pairs and code for a protein with
________ amino acids.
a. 90; 90
b. 270; 30
c. 270; 90
d. 90; 270
11. Independent virus particles (virion)
a. do not contain nucleic acids
b. do not carry out metabolism
c. do not contain ribosomes
d. a, b, and c are all true
e. only b and c are true
12. Viruses that infect bacteria are called
a. retroviruses
b. bacteriorhodopsin
c. bacteriochlorophyll
d. bacteriophage
13. Enzymes that bind DNA fit in the
a. major groove
b. minor groove
c. anti-parallel strand
d. stem-loop
14. Viruses may be as small as
a. 0.02 nm
b. 0.02 m
c. 0.02 mm
d. 0.02 inches
15. The type of infection caused by the herpes virus is best characterized as
a. Lytic
b. Tumerogenic
c. Persistent
d. Latent
16. The virus that poses the largest health threat to human beings, in terms of number of
people that have died in the 20th century, is
a. HIV
b. rhabdovirus
c. orthomyxovirus
d. Ebola virus
17. The type of bacterial virus which is covalently inserted into its host’s DNA is called
a. an Hfr strain
b. temperate phage
c. macrophage
d. virulent phage
18. The last protein expressed during a lytic infection is
a. sigma factor
b. nuclease
c. lysozyme
d. DNA polymerase
19. A piece of double stranded DNA has 14% Adenine bases. Which of the following
would not be true?
a. there would be 36% cytosine in the DNA
b. there would be 14% uracil in the DNA
c. there would be 36% guanine in the DNA
d. none of the above, all are true in the DNA
20. Although uncommon, double stranded RNA “hair pin” or stem loop structures do
occur in
a. mRNA
b. tRNA
c. rRNA
d. all of the above
e. none of the above
21. Which of these is not normally competent for transformation?
a. E. coli
b. Bacillus
c. Haemophilus
d. Streptococcus
22. Which is not a feature of the life cycle of lytic T4?
a. early synthesis of sigma factors and polymerases
b. DNA replication
c. induction
d. late synthesis of capsomeres, stalk, and tail fibers
23. Generalized transduction involves
a. specific genes only
b. a high frequency of gene exchange
c. homologous sequences
d. temperate infections
24. When lysogenized the bacterial host
a. is immune to further infection
b. may produce additional toxins as with diptheria and scarlet fever
c. can reproduce indefinitely
d. all of the above
e. none of the above
25. 2 free points
26. 2 more free points
True or False (1 point each) Place the whole word True or the whole word False before
each of the following statements indicating their validity
___________ Transcription and translation are separated by a membrane in prokaryotes.
___________ Eukaryotic genes contain non-coding regions called introns.
___________ Translation is carried out by ribosomes
___________ RNA processing involves addition of 5’caps and 3’tails.
___________ Supercoiling in eukaryotes does not involve histone protein
___________ Eukaryotic genes are grouped together in operons
___________ Mutations are the primary means by which variation arises in eukaryotes
___________ Codons are normally larger than transposons
___________ Introns occur in prokaryotic genes.
___________ Sigma factors are part of the ribosome.
___________ Complementary strands of DNA are identical in base composition
___________ Complex viruses have an envelope that is taken from the host cell
___________ BI 200 (micro) is harder than BO 200 or ZO 200
___________ BI 200 is more fun than BO 200 or ZO 200
___________ BI 200 is more relevant than BO 200 or ZO 200
10 points - In studying several unusual organisms found on a meteorite from Mars you
are able to sequence their entire genomes. Given the information below, 1) indicate if
each is most likely prokaryotic, eukaryotic, or virus; and 2) name any genetic elements
indicated.
Organism 1 – Contains a single piece nucleic acid which is 6,800 bases of single stranded
RNA. It is surrounded by protein.
1)
2)
Organism 2 – This organism contains two distinct type of nucleic acid. The first is a
circular molecule with 1.4 x 106 base pairs of double stranded DNA. There is a single
copy of this element. There is an average of 20 copies of a smaller element, 8,600 base
pairs of DNA, and it is also circular.
1)
2a)
2b)
Organism 3 – This organism contains 3 pairs of linear pieces of DNA with a total of 4 x
108 base pairs. Within the sequence, there is a 300 base segment that is repeated 100,000
times.
1)
2a)
2b)
Organism 4 – 3 x 107 base pairs of DNA distributed among 4 pairs of linear pieces of
DNA. There is another genetic element of 10,000 base pairs of linear DNA. There is
also another genetic element that is a sequence of 1200 base pairs of DNA and occurs
twice in the chromosome, and once in the smaller linear piece of DNA.
1)
2a)
2b)
Organism 5 – 1.8 x 106 base pairs of DNA found in a single linear chromosome. There is
one copy per cell. Some cells have an additional element of 48,000 base pairs always
inserted in the same spot in that chromosome.
1)
2a)
2b)
1 point each. Fill in the blank from the
viruses listed on this page. There may
be more than one correct answer, and
you may use an answer more than once,
but put only one answer for each.
_________________________________
A sexually transmitted disease that can
cause cervical cancer
_________________________________
Any bacteriophage
_________________________________
Exhibits an unusually wide range of
vertebrate hosts
_________________________________
Any icosohedral virus
_________________________________
Any disease caused by a prion
_________________________________
Any helical bacteriophage
_________________________________
Your favorite virus
_________________________________
Any enveloped virus
_________________________________
Your least favorite virus
_________________________________
Any complex virus
_________________________________
HIV is this type of virus
_________________________________
A temperate bacteriophage
_________________________________
Causes a lytic infection in bacteria
_________________________________
Causes a lytic infection in people
_________________________________
Poliovirus is an example of this type of
virus
_________________________________
Causes a persistant infection
_________________________________
The type of virus that causes SARS is
thought to be
_________________________________
Causes chicken pox
, Beta
, epsilon
, lambda
Adenovirus
BSE
Chronic wasting disease
Corona virus
Creutzfeldt-Jakob
Ebola virus
Hepatitis A
Hepatitis B
Herpesvirus
HIV
kuru
Lambda
M13
Mu
Orthomyxovirus
Papilloma virus (HPV)
Parvovirus
Picornavirus
Poxvirus
Retrovirus
Rhabdovirus
Rhinovirus
scrapie
T4
Match the enzyme or protein that
interacts with DNA to its function or
property.
A. Core enzyme
_____ Creates supercoiling in
prokaryotes
B. DNA pol I
_____ Removes supercoiling in
prokaryotes
C. DNA pol III
_____ Mediates strand exchange during
homologous recombination
D. DNase
_____ Responsible for replication of the
chromosome
E. Histone
_____ Involved in supercoiling of
eukaryotes
F. RecA
_____ ssbp
G. Sigma factor
_____ DNA repair enzyme
H. Single stranded binding protein
_____ Recognizes start of gene for
transcription
I. Topoisomerase I
_____ 2’
J. Topoisomerase II (gyrase)
_____ Degrades DNA