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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, t... 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 ability of viruses to infect different species of frogs may be attributed to mutations within the viral DNA or RNA. These mutations can lead to alterations in the structure of the viral attachment proteins, allowing them to bind to receptors present on the cells of other frog species. Such evolutionary adaptations enable the virus to exploit new hosts.
Step 2
Step 3
Explain how determining the genome of the viruses could allow scientists to develop a vaccine.
Answer
By determining the genome of the viruses, scientists can identify the genetic sequence that encodes for viral proteins. This information can be crucial in identifying potential antigens that could be used in a vaccine, enabling the immune system to recognize and combat the virus effectively.
Step 4
Describe how the B lymphocytes of a frog would respond to vaccination against Ranavirus.
Answer
Upon vaccination, B lymphocytes in the frog would first recognize the viral antigens. These B cells would then undergo mitosis to produce clones. Subsequently, the plasma cells derived from these B cells would release specific antibodies against the Ranavirus, aiding in the neutralization of the virus. Ultimately, memory B cells would be generated to ensure a prompt response during future encounters with the virus.