Bacterial Genetics

match the analytic method with the description

* DNA fingerprinting/profiling = demonstrates unique patterns of DNA fragments in a gel. * polymerase chain reaction(PCR) = amplifies a specific DNA sequence so that there are enough coples that they can be readily detected if present. * DNA sequencing = determines the order of nitrogenous bases in DNA. * DNA probes = detects specific short DNA sequences characteristic of a specific microorganism

match each of the items needed for PCR with their function in the reaction

* template DNA strand = provides the target sequence which will be amplified * primers = direct the DNA polymerase to the target sequence and provide starting material for DNA polymerase to add on to * thermostable polymerase = synthesize new DNA strands * thermocycler = controls and quickly modifies the reaction temperature as needed * free deoxynucleotides = building block that are added to form the new DNA strands

match the inoculated agar plates with their expected growth after incubation

-pGLO on LB = very dense white bacterial growth +pGLO on LB/amp = white bacterial colonies -pGLO on LB/amp = no growth +pGLO on LB/amp/ara = green fluorescent bacterial colonies

place the steps of one PCR cycle into the correct order

1. denaturation 2. priming 3. extension

the following steps are completed when preparing a sample for PCR. place the steps in the correct order

1. label microcentrifuge tubes 2. add DNA samples to microcentrifuge tubes using a new micropipet tip for each sample 3. add prepared master mix containing Taq polymerase, primers, deoxynucleotides, and buffer to microcentrifuge tubes 4. place PCR tubes into thermocycler, set program, and start

order the following general steps of a transformation exercise

1. label two tubes as +pGLO and -pGLO 2. add bacteria to +pGLO and -pGLO tubes 3. add plasmid to the +pGLO tube only 4. move the -pGLO and +pGLO tubes from ice to water bath 5. move the -pGLO and +pGLO tubes from the water bath to ice 6. add LB broth to both tubes 7. inoculate plates of LB, LB/amp, and LB/amp/ara agar as labeled

how should PCR products be stored after completion of PCR, prior to gel electrophoresis

4C

which of the following best portrays the direction of genetic information flow, according to the central dogma of biology

DNA -> RNA -> Protein

which of the following are correctly paired

GFP gene--fluorescent green protein bla gene--ampicillin resistance

match the type of medium with its description

LB agar = nonselective medium for bacteria LB/amp agar = selective medium containing an antibiotic to inhibit the growth of nonresistant cells LB/amp/ara agar = selective medium with added antibiotic and sugar to select for transformants and allow full plasmid expression

which of the following is accomplished by use of PCR

a specific sequence of DNA can be amplified a billion fold

indicate the four nitrogenous bases that are found in DNA

adenine, guanine, cytosine, thymine

which of the following are correct steps in transformation process

bacteria is added to both +pGLO and -pGLO tubes; move the -pGLO and +pGLO tubes from ice to water bath to ice

primers provide the specific location where DNA synthesis will ___

begin

where should the micropipet tip be when delivering a DNA specimen into a well in an agarose gel

below the buffer surface, in the upper portion of the well

which of the following are needed to cast the agarose gel

comb, liquefied agarose, gel tray

the bonds that join the nucleotides in DNA to form the sugar-phosphate backbone are ___ bonds

covalent

which of the following are included in the master mix used to perform PCR

deoxynucleotides primers buffer taq polymerase

select the three components of a nucleotide in DNA

deoxyribose, nitrogenous base, phosphate

which of the following are potential applications of PCR

detection of DNA during crime scene analysis. detection and identification of infectious agents in patient samples. detection of DNA from victims of massive disasters.

which of the following is used to stain the DNA in a gel for viewing after electrophoresis

ethidium bromide

a single nucleotide change in a DNA sequence is not enough to alter any protein structure in an organism

false

all RNA molecules serve as templates for protein synthesis

false

all mutations result in phenotypic change in an organism

false

indicate the items needed for PCR

free deoxynucleotides thermostable DNA polymerase primers template DNA with target sequence

which of the following can be used to detect the products of PCR

gel electrophoresis

the deliberate manipulation of an organism's genome in the laboratory is specifically known as ___

genetic engineering

human genes can be introduced into bacterial cells via transformation, after which the bacteria cells express the human gene, producing a human protein such as insulin or growth hormone. the bacterial cell is described as ___

genetically-modified, a recombinant cell

how is the agarose prepared prior to pouring the gel

it is dissolved into buffer by heating

how can you recognize a transformed bacterial cell from a non transformed bacterial cell

it will grow on agar with added ampicillin and may appear green

what is mixed the PCR samples just prior to loading them into the gel for electrophoresis

loading dye

a single nucleotide change in the original sequence of DNA is a ___

mutation

when positioning the gel in the electrophoresis chamber, the wells should be closet to the ___ electrode

negative

following PCR, the products were loaded into a gel and electrophoresis was performed. following staining of the gel, no band of DNA was observed. based on this observation, was the desired sequence successfully amplified

no

the progress of the DNA fragments through the gel can be monitored by ___

observing the movement of the bromophenol blue loading dye

when a gene of interest from one organism is introduced into a plasmid, the plasmid is referred to as a ___ plasmid

recombinant

plasmids used as cloning vectors often include a gene for antibiotic resistance, this makes it easier to isolate bacterial cells that have been successfully transformed with the plasmid by using a medium containing the same antibiotic. such an antibiotic-containing medium would be described as ___

selective

match the reagents used in the master mix with their purpose in the polymerase chain reaction

taq polymerase = heat-stable enzyme that builds the new DNA molecules dNTP mixture = free nucleotides used to build the new DNA molecules primers = short DNA sequences that direct the synthesis of the target DNA buffer = a reagent used to enhance the activity of enzymes in the mixture

primers selected for PCR must hybridize with ___

the DNA flanking either end of the target sequence

why is the bacterial growth white when +pGLO is plated onto LB/amp agar

the cells cannot transcribe the GFP gene without the presence of arabinose

if arabinose was accidentally left out of the LB/amp/ara plates, what would happen when +pGLO cells were plated on the medium

the cells would be white instead of green/fluorescent

in which of the following ways does the gene for sickle cell hemoglobin differ from the gene for normal hemoglobin

there is a single nucleotide difference

what would be the consequence of not including a lane with the DNA ladder on an electrophoresis gel

there would be no way to determine the size of the fragments

what is the purpose of the -pGLO on LB/amp plate

this plate can be compared to the -pGLO on LB agar plate to show that the cells are not naturally resistant to ampicillin this plate can be compared to the +pGLO on LB/amp plate to show that transformation confers

the process of copying a strand of DNA to form a strand of RNA is called

transcription

genes for human growth hormone and for human insulin have been placed into plasmids and introduced into bacteria by means of ___

transformation

the process by which a bacterial cell picks up small pieces of DNA from the surrounding environment is referred to as

transformation

E. coli cells are made competent for transformation by ___ and ___

treating them with calcium chloride; subjecting them to a brief heat shock

UV illumination is necessary to view ethidium bromide-stained DNA in an electrophoresis gel

true

different species of microorganisms as well as different strains within a species can usually be distinguished by genetic differences

true

if growth appears on the LB/amp plate labeled as -pGLO, what might explain this unexpected result

you accidentally inoculated the plate from the +pGLO tube the ampicillin is actually missing from the medium the original bacterial cells were naturally resistant to ampicillin

how would you explain a lack of expected growth on the control -pGLO/LB plate

you forgot to add bacterial cells to the -pGLO tube