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After filtering a liquid plant extract, the scientists could see the virions using the light microscope.
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After filtering a liquid plant extract, the disease was still transferred to a healthy plant.
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After filtering a liquid plant extract, the virus cells multiplied.
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After filtering a liquid plant extract, scientists were able to trace historical footprints.
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Advances in technology provide historic evidence.
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Biochemical and genetic information provide historic evidence.
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Advances in technology provide new types of information for scientists.
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Advances in technology further prove that viruses have a single common ancestor.
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Measles is a DNA virus, and DNA viruses cause human diseases.
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Dogs do not have glycoproteins.
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The measles virus can’t attach to dog cells.
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Dogs do not get RNA viruses.
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behave in a similar manner
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look very similar
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connect with living things
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are based on the type of disease they cause
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AZT blocks the enzyme called HIV protease, which the virus uses to reproduce itself.
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AZT blocks the HIV integrase enzyme, which the virus uses to insert its viral DNA into the DNA of the host cell.
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AZT prevents reverse transcriptase and HIV protease enzyme from functioning inside the body.
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AZT prevents reverse transcriptase from making DNA from the viral RNA genome.
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The lytic cycle can theoretically produce more virions, as the viral genome is incorporated into the host cell’s genome replicating along with the host cell.
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The lysogenic cycle can theoretically produce more virions, as the reproductive cycle of viruses undergoing lysogeny is much faster than the reproductive cycle of viruses following the lytic cycle.
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The lysogenic cycle can theoretically produce more virions, as the viral genome is incorporated into the host cell’s genome and is replicated along with the host cell.
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The lytic cycle can theoretically produce more virions, as the prophage following the lysogenic cycle ultimately gets excised from the host cell’s genome and enters the lytic cycle.
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The person would be at risk of developing chickenpox. Chickenpox is the first infection with the virus before it enters latency in the host.
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The person would be at risk of developing shingles. Shingles is the first infection with the virus before it enters latency in the host.
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The person would be at risk of developing chickenpox. Chickenpox is the first infection with the virus that is already latent in the body.
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The person would be at risk of developing shingles. The virus enters the person and gets activated when a person with shingles comes in close contact.
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The attachment step is the most critical, as infection cannot begin if virus does not attach to the host cell.
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The replication step is the most critical as this step directs protein synthesis.
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The assembly step is the most critical because new virions are assembled to infect cells.
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The entry step is the most critical as nucleic acid of virus needs to enter the host cell naked, leaving the capsid outside.
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Measles can cause meningococcal disease, which causes severe headaches, seizures and in severe cases can be life-threatening.
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Measles can cause variant Creutzfeldt–Jakob disease, which causes severe headaches, seizures and in severe cases can be life-threatening.
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Measles can cause encephalitis/meningitis, which causes severe headaches, seizures and in severe cases can be life-threatening.
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Measles can cause Legionnaires’ disease, which causes severe headaches, seizures and in severe cases can be life-threatening.
The graph shows the mutation rates of different viruses and bacteria. The ss stands for single strand, ds for double strand, and retro for retroviruses (RNA viruses which transcribe DNA and add it to host's DNA).
Note the viroids at the top left of the graph. These particles infect flowering plants. Based on the trends in this graph, make a prediction about viroid structure.
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Viroids have comparatively large sizes and complex genomes.
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Viroids have large sizes, but have tiny genomes.
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Viroids have a large genome packed in a small structure.
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Viroids have small genomes and are extremely small.
The graph shows the mutation rates of different viruses and bacteria. The ss stands for single strand, ds for double strand, and retro for retroviruses (RNA viruses which transcribe DNA and add it to host's DNA).
The SARS-CoV-2 virus that caused the 2020 pandemic is a single stranded RNA virus with positive polarity (ss+RNA). Its mutation rate is comparatively low, when considering ss(+)RNA viruses.
Based on the patterns you see in the graph, make a prediction about the genome size of the SARS-CoV-2.
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It has a genome size between 100 and 1,000 nt, most likely closer to 1,000 nt.
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It has a genome size between between 1,000 and 10,000 nt, most likely around 5,000 nt.
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It has a genome size between slightly below 10,000 nt.
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It has a genome size between above 10,000 nt.
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Surgery with instruments previously used in a patient with vCJD that were not adequately sterilized and contaminated pineal growth hormones taken from human pineal glands from infected cadavers.
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Through human consumption of infected meat and contaminated pituitary growth hormones taken from human pituitary glands from infected cadavers.
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Surgery with instruments previously used in a patient with vCJD that were not adequately sterilized and contaminated pituitary growth hormones taken from human pituitary glands from unwell individuals.
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Surgery with instruments previously used in a patient with vCJD that were not adequately sterilized and contaminated pituitary growth hormones taken from human pituitary glands from infected cadavers.
The image shows two proteins involed in the bovine spongiform encephalopathy (BSE, the mad cow disease). The protein on the left is healthy. The protein on the right is accumulating extra plated sheets, which cause it to become nonfunctional.
What agent would be causing this fold on the protein?
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Bacteria.
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Viruses.
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Viroids.
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Prions.
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DNA or RNA, though present, is not transmitted when a prion causes infection.
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The prion does not contain any DNA or RNA.
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Only parts of DNA or RNA are transmitted in a prion.
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Far more protein than DNA or RNA is transmitted in a prion.