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Viruses are responsible for many diseases - VCE - SSCE Biology - Question 8 - 2007 - Paper 1
Question 8
Viruses are responsible for many diseases. a. Name one natural feature of the body that acts as a first line of defence when a person comes in contact with a pathog... show full transcript
Worked Solution & Example Answer:Viruses are responsible for many diseases - VCE - SSCE Biology - Question 8 - 2007 - Paper 1
Step 1
a. Name one natural feature of the body that acts as a first line of defence when a person comes in contact with a pathogen.
Answer
One natural feature of the body that acts as a first line of defence against pathogens is the intact skin. The skin provides a physical barrier that prevents the entry of harmful microorganisms.
Step 2
b. Describe the role of interferons.
Answer
Interferons are proteins produced by cells in response to viral infections. Their role is to protect neighboring cells from becoming infected by stimulating them to produce antiviral proteins. This helps to enhance the overall immune response and increase resistance to further infection.
Step 3
c. In the design of the vaccine, what feature prevents the virus-like particles infecting cells and causing disease?
Answer
The vaccine is designed with virus-like particles that lack the necessary nucleic acid, meaning they cannot replicate or infect the host cells. This prevents any risk of generating a live infection while still stimulating an immune response.
Step 4
d. What is the purpose of injecting some women with a saline solution?
Answer
The purpose of injecting some women with a saline solution is to serve as a control group for the study. This allows for comparison between those who received the vaccine and those who did not, ensuring that any observed immune response can be attributed to the vaccine itself.
Step 5
e. Why does the antibody response increase with each vaccination?
Answer
The antibody response increases with each vaccination because subsequent doses stimulate memory B cells, which recognize the antigen more effectively. This results in a faster and more robust production of antibodies during subsequent exposures to the same antigen.