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You have isolated and characterized a new virus and you want to know how to classify it among
the known viruses. All of the following are appropriate questions to ask EXCEPT: - Answer
What symptoms does it cause when it infects a host?
SARS-CoV-2 infects human cells by one of two methods: - Answer - an endocytosis pathway
- a receptor-based fusion
Which of the following appropriately describe viruses? - Answer They can have an RNA or
DNA genome; they require a host for replication; they contain no organelles; they sometimes
contain a lipid envelope
Although bats are considered the original source of most corona viruses that infect humans, the
viruses typically pass through an intermediate host rather than moving directly from bats to
humans. Why? - Answer The spike proteins on the bat corona viruses don't fit any human
receptors.
Primary/innate immune response is - Answer fast, non-specific, not very effective
Secondary/adaptive immunity is - Answer slow, specific, highly effective
One strategy for treating Covid-19 might be to develop a drug that blocks the ACE2 receptors.
How might such a drug benefit Covid patients? - Answer By reducing the probability of the
virus entering additional cells
One argument against vaccination that is often mentioned states that Covid vaccines may cause
permanent infertility in women. What is the origin of this myth? - Answer Some people are
concerned that the immune system may attack the placenta after vaccination, since the
attachment of placental cells to the uterus involves a protein that, although unrelated to SARS-
CoV-2 spike protein, is known as a "spike protein."
SARS-CoV-2 spike proteins are similar to hemoglobin in what way? - Answer - Both represent
targets for natural selection
- Changes of single amino acids in both can have significant impacts on human physiology and
health.
- Mutations that 'open' the quaternary structures of both lead to increased binding of their
preferred 'substrates.'
- They are both multi-subunit proteins.
, In your community, a new virus has been introduced from Australia, which no one in the
community has had contact with. The only available test for the infection with this virus
determines whether antibodies exist in the blood of the person. Three days ago, you were in
contact with a person infected with this new virus. Can you take the test today and get a reliable
result? - Answer No, because during the initial infections, antibodies are produced only after
4-6 days.
Which of the following statements about COVID-19 vaccination is false? - Answer The
vaccine prevents SARS-CoV-2 infection.
Two hummingbird species, one with a 'low altitude' Hb and one with a 'high altitude' Hb, are
found living at ~2500 meters in the Andes and both forage on the same species of plant.
Because of climate change this food plant's ecological range moves from ~2500 m to ~4000 m.
What will happen to the two hummingbird species when this plant is found only at ~4000 m? -
Answer Both the 'low altitude' and 'high altitude' Hb-containing hummingbirds will follow
the food plant up the mountain; the hummingbirds with the 'high altitude' Hb will continue to
flourish, while the hummingbirds with the 'low altitude' Hb will likely struggle and potentially
crash as a population.
As new vaccines move through the clinical phases (e.g. phase I to phase II to phase III), ... -
Answer ... more and more people are added to the vaccine trial as it moves through the
phases.
What is the role of memory cells in the immune system? - Answer They respond quickly if
you are re-infected with a pathogen that your body fought off in the past.
When you buy packaged meat in a supermarket, the cling wrap that covers the package allows
O2 to pass through. What is the reason for this? - Answer The O2 keeps the myoglobin in the
oxygenated state, which gives the meat a bright red color.
Why is the Myoglobin-O2 dissociation curve not sigmoidal in shape? - Answer Because is
consists only of a single globin unit with one heme
The placental mole and the marsupial mole are separate species that look very similar to each
other: both have large 'hands' that are used for scooping dirt as they dig underground tunnels,
both have very tiny eyes and a short tail, and both have fur that allows movement both forward
and backward in tunnels. These two species are often cited as an example of convergent
evolution. Given this information, which of the following is most likely true? - Answer The
two species of moles evolved these specialized traits independently of each other as a result of
similar selection pressures.