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Worksheetsap bio: 12 genomes + 13 biotechnology - lani t
Total questions: 25
Worksheet time: 13mins
DNA sequences that can jump from place to place within a genome were first discovered in the 1940s by Barbara McClintock. When these sequences change locations within a genome, they can cause mutations leading to changes in the genetic sequence. These elements are known as
plasmids
bacteriophage
vectors
transposons
Microarrays can be used to compare the level of expression of a particular gene under control and experimental conditions. In one type of array, DNA sequences representing all the genes in the genome arrayed on a glass slide. These arrayed DNAs are called targets and they are hybridized with fluorescently red labeled (experimental) cDNA and fluorescent green (control) labeled cDNA made from reverse transcribed messenger RNAs.
In one experiment, mRNA from a strain of antibiotic resistant bacteria (experimental) is converted into cDNA and labeled with red; mRNA from a non-resistant strain of the same bacteria is converted into see DNA and labeled with green. The cDNAs from the resistant and nonresistant cells were combined and hybridized to glass slide containing cDNA.
Which color spot correspond to genes up-regulated in non-antibiotic resistant bacteria?
red
gray
yellow
green
A scientist wants to put a eukaryotic sequence into a prokaryotic host. They add an expression vector. One of its benefits allows for:
down-regulation of foreign gene
heightened replication of prokaryotic host DNA for amplification
a promoter
marker of how much a gene is present such as a dye
In genetic engineering, small loops of DNA called ___ are to be shuffled from one organism to another.
D-loops or displacement loops
DNA splicing
plasmids
transposons
Since bacteria don’t have introns, they lack RNA-splicing machinery. So, they cannot remove said introns from a foreign DNA insert when making the mRNA. If you want to force bacteria to make a eukaryotic protein, you can make a gene without introns. A way to do this is to _______.
switch the bacteria’s genes so that they can splice RNA
use a probe to find a gene without introns
work backward from mRNA to make a version of the gene without introns
use a phage to insert the desired gene into the bacteria
Viruses that attack bacteria are named “bacteriophages.” The term phage originates from Greek phagein, which translates as “to eat”. The phage infection cycle seems to be simple but efficient: a single phage injects its genome into a bacterial cell, switching the cells' program in its favour so the host cell will eventually die and release about 100 new phage particles. If a bacterium became infected, what should element(s) should it release?
lysosomes
restriction enzymes and DNA polymerase
DNA ligase
restriction endonucleases and methyltransferase
In which of the following scenarios would it be advantageous to create + work with a cDNA (complementary DNA) library rather than a genomic library?
a study of the role of noncoding RNA plays in regulating the expression of the coding genes of a genome
a study of a protein involved in a lizard’s eye development + the regulation of the gene that expresses it
a study of the enhancer region of a gene that regulates a snake’s neural development
a study that compares the sequences of introns for the genes of a cat’s fur development shared among different lineages
Which of the following arrangements of the enzymes below represent the order in which they would be used in a traditional gene-cloning experiment that begins with a strand of mRNA and results in the insertion of a cDNA into a bacterial plasmid?
restriction enzyme, reverse transcriptase, DNA polymerase, DNA ligase
restriction enzyme, DNA ligase, reverse transcriptase, DNA polymerase
reverse transcriptase, DNA ligase, DNA polymerase, restriction enzyme
reverse transcriptase, DNA polymerase, restriction enzyme, DNA ligase
Human nerve cells differ from human muscle cells because different sets of genes are expressed; in each type of cell, different genes are transcribed into mRNA and translated into protein. Which of the following techniques would be the most efficient way to identify the genes that these cells express?
use of microarray
gel electrophoresis of DNA fragments
isolating and analyzing all the proteins from each type of tissue
RT-PCR
The immunoglobulin superfamily (IgSF) is a large gene family that are involved in the recognition, binding, or adhesion processes of cells. Members of this family commonly contain a domain known as an “immunoglobulin domain or fold.” How can you explain this common feature in so many molecules?
all of the genes that produce these proteins used to be part of a much larger gene that broke down into smaller ones
these genes are retrotransposons
these genes are introns that experienced mutations
the fold is repetitive because of gene duplication and evolution
The genomes of most eukaryotes are larger and more complex than those of prokaryotes, due to the higher complexity of eukaryotes. However, the genome size of many eukaryotes does not appear to be related to genetic complexity. For example, the genomes of lilies contain more than ten times the amount of DNA that is in the human genome, yet these organisms are clearly not ten times more complex than humans. Why might this be?
the two species evolved at very different geologic eras
lilies have more noncoding DNA
lilies have a higher gene density
lilies are more complex organisms
What is the most probable explanation for the continued presence of pseudogenes in a genome?
they have accumulated mutations to such a degree that they code for different functional products
though they are duplicates of functional genes, they cannot function because they would make inappropriate amounts of protein products
they have significant inverted sequences in between exons, stripping their ability to produce proteins
their inability to produce functional proteins is often the consequence of subsequent genetic alterations
What characteristic of short tandem repeats (STRs) DNA makes it advantageous for DNA fingerprinting?
the number of repeats varies widely from person to person
the sequence of DNA that is repeated varies significantly from specie to specie
the sequence variation is acted upon differently by natural selection in different environments
none of the above
Recombination hotspots are regions in a genome that show elevated rates of recombination relative to a neutral expectation. The recombination rate within hotspots can be hundreds of times that of the surrounding region. What might this information most likely be used for?
for comparisons of orthologs, genes in different species that evolved from a common ancestor, to see if there are changes in function
to be used in the field of metagenomics
to find correlations between homologs and pseudogenes
for genetic mapping, which can document the way in which recombination rates vary over a genome
A scientist wants to determine the function of a certain sequence of DNA in a snake. What might be the most reasonable approach?
use RT-PCR to amplify and examine the sequence
look for an identical sequence in another species, and perform a knockout experiment of this sequence in that species
genetically engineer a mouse with a copy of the sequence and examine its phenotype
prepare a genetically engineered bacterial culture with the new sequence
DNA biotechnology has allowed scientists to identify many human genetic disorders, such as hemophilia and cystic fibrosis. When the gene has been amplified by PCR, the DNA is sequenced to determine whether the individual has the disease. If scientists decide to create a test for a new genetic disease, what must first occur before PCR can be used to test for that disease?
the genome must be run through gel electrophoresis
the gene for the disease must be located in the genome
the complementary sequence specific to the gene must be created in the lab through cDNA
it must be recombined into a bacterial cell through recombination
In gel electrophoresis, the DNA fragments will migrate towards the
anode or positive electrode
cathode or negative electrode
anode or negative electrode
neutral electrode
The charge present on the DNA backbone is negative. The force required to accelerate the molecules towards anode is directly proportional to number of
sugar molecules
nitrogenous bases
phosphate groups
both A and C
How is the size of molecules under analysis measured?
by measuring the distance moved using a ruler
by measuring the amount of dye seen under analysis
by running a standard molecule, whose size is already known
none of the above
If the amount of agarose added is more, the molecules under analysis should have following characteristics:
small size
large size
size has no relation w/ the amount of agarose
this depends on the amount of molecules under analysis
A plasmid has two antibiotic resistant genes - ampicillin resistant and chloramphenicol resistant - if the plasmid grows in ampicillin containing medium, but not in chloramphenicol, what can be concluded?
the insert is not present at all
the insert is present in ampicillin but not in chloramphenicol gene
the insert is present in chloramphenicol but not in ampicillin gene
the insert is present between both of the genes
Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence. The name was first used by Raphaël Dubois who invented the words luciferin and luciferase, for the substrate and enzyme. Which of the following can it be used for?
track tumor cells
follow viral infections
track bacterial infections
analyze gene expression
Electroporation is one of the methods used for taking up the DNA by the cells. It constitutes of
increased efficiency than both natural and chemical methods over long periods of time
decreased efficiency than both natural and chemical methods over long periods of time
causing the least amount of damage in comparison to other methods
inserting the DNA into the cells through an electric shock
Blots are techniques for transferring macromolecules onto a carrier so they can be separated, routinely used in molecular biology for detection of a specific sequence in samples. Often, DNA needs to be removed from the gel to the solid support. The process can be termed as:
southern blotting
northern blotting
western blotting
eastern blotting
In PCR, _______ is from a thermophilic bacterium. It is highly resistant to heat, and does not denature easily.
DNA Polymerase I
DNA Polymerase II
Taq
Sigma
