Measles is a communicable disease caused by a virus - Edexcel - GCSE Biology Combined Science - Question 5 - 2020 - Paper 1
Question 5
Measles is a communicable disease caused by a virus.
(a) What can a virus also be classified as?
A
B
C
D
(ii) Give one reason why measles is described as ... show full transcript
Worked Solution & Example Answer:Measles is a communicable disease caused by a virus - Edexcel - GCSE Biology Combined Science - Question 5 - 2020 - Paper 1
Step 1
What can a virus also be classified as?
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Answer
A virus can be classified as: C - a pathogen. Pathogens are microorganisms that can cause disease, and viruses fall into this category.
Step 2
Give one reason why measles is described as a communicable disease.
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Answer
Measles is described as a communicable disease because it can be easily transmitted from one person to another through respiratory droplets when an infected person coughs or sneezes.
Step 3
Which type of cell is destroyed by the HIV virus?
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Answer
The type of cell that is destroyed by the HIV virus is C - white blood cell. Specifically, HIV targets CD4 T-helper cells, which are crucial for the immune response.
Step 4
Describe how the specific immune system defends the body against disease.
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The specific immune system defends the body against disease through several mechanisms:
Recognition of pathogens: Pathogens have specific antigens that are recognized by lymphocytes (T cells and B cells).
Antibody production: Once the antigens are recognized, B cells produce antibodies that specifically target the pathogen, leading to its neutralization or destruction.
Memory response: After the initial infection, memory cells remain in the body. If the same pathogen re-invades, these memory cells enable a quicker and more effective immune response, often preventing reinfection or reducing severity.
