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BIO250_Saylor_V5
Unit 24: Genetic Engineering and Recombinant DNA
Started on Wednesday, October 13, 2021, 10:37 AM
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Completed on Wednesday, October 13, 2021, 11:02 AM
Time taken 25 mins 18 secs
Grade 85.50 out of 90.00 (95%)
Question 1
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Eutrophication
Select one:
a. is characterized by heavy surface algal blooms.
b. restricts the O2 supply to water below the surface.
c. occurs when there are excess nutrients in aquatic ecosystems.
d. causes massive die-off of fish and invertebrates.
e. All of the choices are correct.
Question 2
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Considering the human body as an ecosystem, which of the following statements is
incorrect?
Select one:
a. Microbes act as producers, consumers, and decomposers within the human
ecosystem.
b. Energy for the human microbiome derives exclusively from the food we eat.
c. The microbiota in the human gut is comprised of heterotrophs.
d. The human ecosystem lacks an autotrophic niche.
Question 3
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Plastic marine debris was collected from multiple sites in the ocean and examined with
electron microscopy and next-generation sequencing. These techniques revealed microbial
communities growing on the plastics. Which of the following statements is correct regarding
these communities?
Select one:
a. At least one member of the community must synthesize an enzyme to degrade the
hydrocarbon comprising the plastic.
b. The community within the plastic must be very similar to the community in the
surrounding ocean waters.
c. There are no bacteriophage that use these microbes as hosts, as viruses are rare in
marine ecosystems.
d. These communities are very likely to be pure cultures, as plastics have been synthesized
precisely because they are resistant to microbial degradation.Question 4
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Which of the following statements regarding the infection of root hairs by Rhizobium species
is incorrect?
Select one:
a. Attachment of Rhizobium cells to plant root hair cells induce curling of the root hair.
b. The presence of Rhizobium triggers the formation of syncytial cells.
c. Nodules begin to form in the roots as both plant and bacterial partners differentiate.
d. This is a mutualistic relationship between plant and bacteria.
Question 5
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Carbon dioxide (CO2) is
Select one:
a. removed from the atmosphere during photosynthesis.
b. a source of carbon for autotrophs.
c. returned to the atmosphere during respiration and fermentation.
d. used by marine organisms to make limestone for their hard shells.
e. All of the choices are correct.
Question 6
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Methane can be produced from agricultural or industrial products by ______.
Select one:
a. anaerobic respiration
b. oxidation of nitrogen gas
c. fermentation
d. glycolysis
Question 7
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Place the steps of the water purification process in order.
Select one:
a. Filtration and settling, chemical disinfection, aeration, release into a water reservoir
b. Aeration, filtration and settling, chemical disinfection, release into a water reservoir
CORRECT
c. Chemical disinfection, aeration, filtration and settling, release into a water reservoir
d. Release into a water reservoir, aeration, filtration and settling, chemical disinfection
Question 8
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Which of the following is not true of industrial microbiology?
Select one:
a. Primary metabolites are essential to a microbe's function.
b. Secondary metabolites include amino acids.
c. Growth environment is enhanced to increase metabolite synthesis.
d. Select microbial strains are not controlled by feedback mechanisms.
Question 9
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A device in which mass cultures are grown, reactions take place, and product develops is
a(n) ______.
Select one:
a. sparger
b. activator
c. fermentor
d. incubator
Question 10
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An organism used to make a variety of industrial enzymes by fermentation is ______.
Select one:
a. Penicilliumb. E. coli
c. Salmonella
d. Aspergillus
Question 11
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Full induction of the lactose operon requires
Select one:
a. lactose present.
b. lactose and glucose present.
c. lactose present without glucose.
d. lactose and arabinose present.
Question 12
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Base pairs in DNA are held together by ______ bonds.
Select one:
a. peptide
b. nonpolar covalent
c. polar covalent
d. hydrogen
e. sulfhydrylQuestion 13
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Which of the following is incorrect about termination codons?
Select one:
a. They are also called nonsense codons.
b. They are the location where the bond between the final tRNA and the polypeptide is
broken.
c. They include AUG.
d. They are UAA, UAG, and UGA.
e. They do not have corresponding tRNA.
Question 14
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The mechanism of DNA synthesis differs between the two new daughter strands during
replication. This is due to the fact that
Select one:
a. the DNA strands run antiparallel to each other and the DNA polymerase can only add
nucleotides to the 3' end of the growing strand.
b. one RNA primer attaches to the 5' end of the parent strand and the other primer to the 3'
end.
c. both RNA primers attach to the 3' end of the template strands, which are at opposite
ends from each other.d. both daughter strands can't extend toward the replication fork because there would not
be room for two DNA polymerase enzymes.
Question 15
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A screening system called the _______ test is used for detecting chemicals with
carcinogenic potential.
Select one:
a. Koch
b. Ames
c. mutation
d. cancer
e. Iowa
Question 16
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Why is an enzyme from a thermophilic bacterium used in PCR?
Select one:
a. The enzyme makes DNA that is more similar to human DNA.
b. It is cheaper to obtain from live microorganisms than producing the enzyme in a lab.
c. This thermohile's enzyme will synthesize DNA.
d. DNA is replicated at a high temperature that denatures most proteins.
Question 17Correct
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Transgenic animals are referred to as _____ modified organisms.
Select one:
a. genetically
b. naturally
c. chemically
d. physically
Question 18
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Sequences of DNA that are identical when read from the 5' to 3' direction on one strand and
the 3' to 5' direction on the other strand are ______.
Select one:
a. palindromes
b. reverse transcriptases
c. restriction endonucleases
d. ligases
e. DNA polymerases
Question 19
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One reason the field of proteomics is continually evolving following the systematic study of
an organism's genome is because
Select one:
a. it became apparent that while the organism's genome is relatively stable, protein
expression in an organism is constantly changing.
b. once the genome had been sequenced, all protein expression was understood.
c. it became apparent that protein expression is relatively uniform, whereas the genome is
constantly changing.
d. the expression of proteins is fixed in each organism so sequencing the genome is
essential to understanding phenotypes.
Question 20
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DNA fragments can be separated in gel electrophoresis because
Select one:
a. nitrogenous bases have a net positive charge.
b. nitrogenous bases have a net negative charge.
c. phosphate groups have a net positive charge.
d. phosphate groups have a net negative charge. [Show Less]