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In Europe, viruses have infected a large number of frogs of different species - AQA - A-Level Biology - Question 3 - 2020 - Paper 3
Question 3
In Europe, viruses have infected a large number of frogs of different species. The viruses are closely related and all belong to the Ranavirus group. Previously, th... show full transcript
Worked Solution & Example Answer:In Europe, viruses have infected a large number of frogs of different species - AQA - A-Level Biology - Question 3 - 2020 - Paper 3
Step 1
Suggest and explain how the viruses became able to infect other species of frog.
Answer
The viruses likely underwent mutations in their genetic material, enabling them to adapt to different receptors found on the cells of various frog species. These mutations could change the viral attachment proteins, allowing them to bind to these alternative receptors effectively.
Step 2
Step 3
Explain how determining the genome of the viruses could allow scientists to develop a vaccine.
Answer
By determining the genome, scientists can identify specific proteins that are essential for the virus's life cycle and pathogenesis. This information helps in selecting potential antigens to be included in a vaccine to stimulate an immune response.
Step 4
Describe how the B lymphocytes of a frog would respond to vaccination against Ranavirus.
Answer
B cells will bind to the Ranavirus antigens through their specific receptors. Following this binding, B cells will divide by mitosis to produce clones. Some of these clones will differentiate into plasma cells that release monoclonal antibodies, while others will develop into memory B cells, ensuring long-term immunity.