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Yellow fever is caused by a virus transmitted through the bite of a particular species of mosquito - VCE - SSCE Biology - Question 7 - 2012 - Paper 1
Question 7
Yellow fever is caused by a virus transmitted through the bite of a particular species of mosquito. a. Would you describe a virus as a cellular or non-cellular path... show full transcript
Worked Solution & Example Answer:Yellow fever is caused by a virus transmitted through the bite of a particular species of mosquito - VCE - SSCE Biology - Question 7 - 2012 - Paper 1
Step 1
Would you describe a virus as a cellular or non-cellular pathogen? Justify your answer.
Answer
A virus is classified as a non-cellular pathogen. Unlike cellular organisms, viruses are not made of cells and do not possess cellular structures. They consist of genetic material (DNA or RNA) enclosed in a protein coat and rely on a host cell for replication. Viruses cannot carry out metabolic processes on their own and must infect a host to reproduce, highlighting their non-cellular nature.
Step 2
Describe two ways in which the first line of defence of their body would protect against an infection by this virus.
Answer
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Intact Skin: The skin acts as a physical barrier, preventing the entry of pathogens, including viruses, into the body. If the skin is intact, it helps to keep the virus out.
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Mucus Secretion: The secretion of mucus in the respiratory tract can trap pathogens. Ciliated epithelial cells then help to move the mucus out, carrying away any particles, including viruses, and preventing their entry into the respiratory system.
Step 3
Explain why this precaution is taken and what course of action Australian authorities may take for an unvaccinated person wanting to re-enter Australia.
Answer
This precaution is taken to prevent the importation and spread of yellow fever, a disease that can have severe health implications. Ensuring that travelers are vaccinated reduces the risk of outbreaks in Australia. Upon arrival, unvaccinated persons may be quarantined for a period and monitored for symptoms of the virus. Authorities may also require proof of vaccination before allowing re-entry to ensure public health safety.