Download BIO208 Bacterial Genetics Worksheet 1 1. . Fill in: Transformation

BIO208
Bacterial Genetics Worksheet
1. . Fill in: Transformation
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Transduction
Conjugation
_______________a. naked DNA is involved
_______________b. faulty head stuffing may occur
_______________c. involves exconjugants
_______________d. adsorption and injection of genetic material
_______________e. competent cells required
_______________f. an F plasmid encodes attachment proteins
_______________g. used to construct the E. coli minute map
_______________h. a pilus is produced
_______________i. lytic cycle entered in response to stress
_______________j. may be specialized or general
_______________k. requires cell to cell contact
_______________l. mediated by a virus
_______________m. known as parasexual mating
_______________n. requires competent cells
_______________o. involves a phage
ANS. a. TF b. TD c. Con d.TD e. TF f.Con g.Con h.Con i.TD j.TD k.Con l.TD m.Con n.TF o.TD
2. Fill in - you may use a term more than once, or not at all
homologous recombination
extrachromosomally (episomally)
F Factor (plasmid)
Hfr strain
generalized
phage packaging
adenovirus
adsorption
F+ cell
F minus (F-)
lysogeny
a. the reciprocal exchange of DNA between two DNA fragments of identical (or at least close to identical) sequences is
called __________________________________
b. A plasmid can be maintained _______________________ or integrate into bacterial chromosome.
c. In ______________ transduction, all bacterial DNA has equal probability of being packaged into progeny phage
d. In ________________, the phage genome integrates into bacterial genome creating a prophage.
e. The ______________ contains ~100,000 base pairs and contains 19 genes that encode for proteins involved in pilus
synthesis and other functions
f. One method of gene therapy uses replication deficient _____________ to deliver a gene to body cells
g. The F factor occasionally integrates randomly into the E. coli chromosome creating a _______
h. In normal conjugation, recipient (female) cells remain __________
i. After a phage engages in _____________, it will inject genetic material into bacterium
j. Lambda bacteriophage assembles new virus during the process of ________________
k. The creation of a knockout mouse uses the process of ________________ to replace DNA with an engineered
construct
ANS
a. hom rec. b. extrac. C. generalized d. lysog e. F factor f. adeno g. Hfr h. F- i. ads
j. phage pack k. hom. Rec.
3. What is the difference between:
a. A bacterial colony and a lawn
b. The log phase and the stationary phase of bacterial growth
c. Minimal media and complete media
d. A conditional mutant and a nutritional mutant
e. Binary fission and parasexual mating
f. A prototroph and an auxotroph
g. A plasmid and a chromosome
h. Transduction and transformation
BIO208 Bacterial Genetics Worksheet
i. A phage and a bacterium
j. An F+, an Hfr, and an F- cell
k. A donor and recipient cell
l. A U tube and a blender
m. Size of F factor and size of bacterial genome
n. Lytic and lysogenic cycle
o. A virulent and a temperate phage
p. Prophage and phage
q. Phage adsorption and phage packaging
r. A cfu and a plaque
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ANSWER ON OWN USING NOTES/TEXTBOOK
4. What is the difference between
a. operon inducer and repressor
b. betagalactosidase and Z structural gene
c. promoter and operator
d.
O and Oc
e. I and If. lactose and glucose
g. negative and positive operon regulation
h. polycistronic and monocistronic (as in humans) mRNA
i. constitutively expressed and regulated genes
ANSWER ON OWN USING NOTES/TEXTBOOK
5. Operons are found in (circle one)
a. Prokaryotes
b. Eukaryotes
6. Fill in using the following choices
lactose
repressor protein
operator
lac Z
promoter
beta galactosidase
a. _____________________________ DNA that binds repressor to prevent transcription
b. _____________________________ DNA that binds RNA polymerase
c. _________________________ binds repressor to allow transcription to occur
d. _____________________________ a structural gene of the operon
e. _____________________________ is bound by lactose
f. _____________________________ a trans acting protein that represses the operon
g. _____________________________ encoded by the I gene
h. __________undergoes a conformational (shape) change which prevents binding to the operator
i. _____________________________ gene that is actively transcribed when derepressed
j. _____________________________ enzyme that cleaves lactose into glucose and galactose
k. _____________________________ 3 DNA elements of the lac operon
l. _____________________________ 2 proteins associated with the lac operon
m. _____________________________ 1 sugar associated with the lac operon
ANS. a. rep b. pro c. lac d. Z e. rep f. rep g. rep h. rep i. Z j. beta k. P, O, Z l. rep, beta m. lac
7. A normal bacterial cell is grown in lactose (sugar) in the absence of glucose. The lac operon is:
a. off (repressed)
b. on (induced)
BIO208
Bacterial Genetics Worksheet
8. A bacterial cell has a lactose operon but the promoter is defective. All else is normal. The bacterium is
transformed with a plasmid that contains a wild type (normal) promoter, amp resistance gene, and origin of
replication. Can the cell utilize lactose? (i.e. is the operon inducible?) Why or why not?
The cell cannot utilize lactose because the promoter is defective. The addition of a normal promoter on a
plasmid cannot substitute because promoters act in cis – the promoter must be upstream of the gene it
regulates, not on a separate piece of DNA.
The operon is not inducible either. The addition of lactose will not result in the transcription of the structural
genes. The lactose will bind the repressor and prevent it from binding to the operator, but the genes cannot be
transcribed without a functional promoter
9. Match the plasmid feature to the gene. You will use some answers more than once.
_____ allows cell to deactivate ampicillin
A. ara C
_____ allows plasmid to replicate autonomously
B. bla gene
R
_____ also called amp
C. ori
_____ allows cells to manufacture GFP
D. GFP gene
_____ regulates the expression of GFP gene
E. multiple cloning site
_____ enables genes to be ligated into plasmid
_____ known as a reporter gene
_____ recognized by a variety of restriction enzymes
_____ a foreign gene not normally found in bacteria
_____ enables jellyfish and other marine organisms to glow
ANSWER: B -- C—B—D—A---E---D----E----D-----D
10. 36 bacterial colonies were observed on a nutrient agar plate. The original sample was 0.1 ml withdrawn
from the culture and diluted 1:1000 prior to plating. Determine the titer (cfu/ml).
ANSWER 36 colonies X 1:1000 dilution = 36,000 total colonies per 0.1 ml = 3,600,000 cfu/ml
11. Why is it not useful to use Salmonella bacteria in phase C?
Growth curve of Salmonella bacteria
ANSWER – phase C is the stationary phase. Bacteria are not in their max growth stage at this
point
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