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Option F
Keegan Murphy
Statement 1.3- Distinguish
Between the Characteristics of the
Three Domains
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Domain Eukarya contains all Eukaryotic cells while Domains
Archaea and Bacteria are prokaryotic. This means that
organisms of domain Eukarya have membrane bound
proteins and DNA that is wrapped about histone proteins.
Archaea and Bacteria are defined as separate because
Archaea have some genes common to prokaryotes and
some of eukaryotes
For example, Archaea has an rRNA sequence that is
different than that of Bacteria.
Archaea also have 3 types of polymerase like eukaryotes
as opposed to the 1 that is typical of Bacteria.
Finally, Archaea are known to have intron segments in their
DNA, like eukaryotes, while prokaryotes do not have intron
segments.
Statement 1.7- Compare the Structure
of the Cell Walls of Gram-positive and
Gram-negative Eubacteria
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Gram-positive and Gram-negative refer to a
positive or negative result in a Gram Staining
test.
In this test bacterial colonies are separated
from one another using a chemical that stains
any bacteria with a significant quantity of
peptidoglycan in their cell wall a violet color.
Bacteria that have peptidoglycan in their cell
walls (Gram-positive) have an extra mesh-like
layer of peptidoglycan, amino acids, and
sugars around their plasma membrane
Statement 1.8- Outline the
Diversity of Structure of Viruses
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A caspid is the protein shell of a virus. Some viruses
have enveloped caspids, protein shells that are
covered in a lipid membrane known as the viral
envelope, while others have naked caspids which
do not have the envelope.
Some viruses (DNA Viruses) replicate by inserting
their own genetic sequence into the DNA of the
host cell while others (RNA Viruses) instead inject
their genetic code into sequences of RNA.
Viruses will insert sections of RNA and DNA that
differ in the amount of strands that they have.
Some will have only one strand and some will
have two strands.
Statement 2.5- Explain the
Consequences of Releasing Raw
Sewage and Nitrate Fertilizer into Rivers
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Sewage contains many different pathogens which
are dangerous if they come into contact with an
individual. This also draws a number of saprotrophs
to break down the organic waste which, in turn,
consumes the water’s dissolved oxygen and
creates BOD (Biochemical oxygen demand)which
kills aquatic oxygen dependent organisms.
Releasing nitrate fertilizers into rivers can cause
eutrophication (excessive algal growth) which can
lead to algal blooming which also consumes all of
the dissolved oxygen in the water and creates
BOD which, again, causes the death or emigration
of oxygen dependent aquatic organisms.
Statement 2.8- Explain the Principles
Involved in the Generation of Methane
from Biomass
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In order to produce methane a number of bacteria are
needed. First, bacteria are needed to convert organic
matter into organic acids and alcohol.
Then, a second group of bacteria is needed to convert the
acids and alcohols into acetate, carbon dioxide and
hydrogen.
Finally, a third group of what is called Methanogenic
bacteria is needed to create methane in the following
chemical reactions:
Carbon Dioxide + Hydrogen -> Methane + Water
Acetate -> Methane + Carbon Dioxide
The conditions that are needed include the absence of
oxygen, a temperature of about 35˚C and a non-acidic pH
Statement 3.2- Explain How
Reverse Transcriptase is Used in
Molecular Biology
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transcriptase is used by reverse
transcribing RNA viruses like retroviruses
 Reverse transcriptase takes the RNA of the
virus and performs the process of
transcription in reverse to form viral DNA
 The viral DNA is then integrated into the
host’s DNA and is used to code for the
replication of the virus.
Statement 3.4- Outline the Use of
Viral Vectors in Gene Therapy
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the process of viral vector gene
therapy, specific viruses are used to
remove harmful sections of DNA and
replace them with healthy DNA.
 One example is in the case of an immune
deficiency condition called SCID where
gene therapy can be used to insert genes
that code for the production of an
enzyme Adenosine Diamenase
Statement 3.5- Discuss the Risks
of Gene Therapy
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The use of viral vectors can trigger cancer
causing genes
If something goes wrong then a gene can be
over expressed and too much of a certain
protein will be made
There is always a potential that the new gene
will be misplaced causing major problems
Gene therapy may stimulate an immune
reaction
Viral vectors can be transferred from person
to person
Statement 4.4- Outline the Symptoms, Method
of Transmission and Treatment of One Named
Example of Food Poisoning
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Salmonella Symptoms: Nausea, Diarrhea,
Vomiting, Abdominal Pain, Fever, Chills,
Headache, Muscle Pains and Blood in the Stool.
Transmission: Salmonella is first contracted through
the consumption of undercooked meat and eggs
but then can be transferred through improper
hand washing/other sanitary procedures.
Treatment: Drinking lots of water to combat
dehydration. If dehydration is severe then fluids
are given intravenously. If the infection spreads
beyond the intestines to the blood then antibiotics
should be administered.
Statement 6.5- Outline the Mechanism of the
Action of Antibiotics, Including the Inhibition of
Synthesis of Cell Walls, Proteins and Nucleic
Acids.
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Cell Walls: Penicillin is a common example. To
perform its task, penicillin breaks apart at the beta
lactam ring in its structure and binds to the
enzymes that synthesize cell walls in bacteria,
causing the cell to explode from osmotic pressure.
Protein Synthesis: Inhibition is carried out by
attacking the bacterial ribosomes which the drug
differentiates from human ribosomes.
Nucleic Acids: Nucleic acid inhibiting antibiotics
bind to the bacterial cell’s DNA or RNA to make it
unreadable which stems the cell’s growth.
Statement 6.6- Outline the Lytic
Life Cycle of the Influenza Virus
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Influenza binds to a cell through the use of specific
receptors
Influenza is taken in through endocytosis
Viral RNA is released into the cytoplasm
RNA is transported to the nucleus where it is copied and
replicated into RNA using a viral enzyme
Some RNA is transported to the cytoplasm where it is
translated to make viral proteins which return to the nucleus
to assemble the caspid
Influenza’s envelope proteins assemble in the cell
membrane. Influenza buds off of these points and uses the
cell membrane as its envelope
Lysis of the cell occurs to release many new influenza units
to attack the other cells in the body.
Statement 6.10- Discuss the Prion
Hypothesis for the Cause of
Spongiform Encephalopathies
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The Prion Hypothesis states that the transmitting
agent of spongiform encephalopathies contains no
nucleic acids and instead is an entity composed of
of misfolded proteins called a prion.
The abnormal protein in the prion causes the disease
Prions can change the shape of other proteins to
cause cell death
The action of these prions causes spongiform
encephalopathies because it causes brain tissue to
decay, leading to memory loss, personality changes,
speech lapses and eventually death.
One example is the disease CJD (Creutzfeldt-Jakob's
Disease) in humans