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22 (6 marks) (a) Describe how phagocytes help protect against pathogens - HSC - SSCE Biology - Question 22 - 2023 - Paper 1
Question 22
22 (6 marks) (a) Describe how phagocytes help protect against pathogens. (b) Explain how antibodies are produced in response to the entry of a pathogen.
Worked Solution & Example Answer:22 (6 marks) (a) Describe how phagocytes help protect against pathogens - HSC - SSCE Biology - Question 22 - 2023 - Paper 1
Step 1
Describe how phagocytes help protect against pathogens.
Answer
Phagocytes are essential components of the immune system that help protect the body from infections. They function by engulfing and enclosing pathogens, such as bacteria, through a process known as phagocytosis. By recognizing non-self substances, phagocytes can identify and target these pathogens. Once a pathogen is engulfed, enzymes inside the phagocyte break down the invading organisms, effectively neutralizing the threat.
Step 2
Explain how antibodies are produced in response to the entry of a pathogen.
Answer
When a pathogen, such as a virus or bacterium, enters the body, it presents foreign protein markers known as antigens. These antigens are recognized as non-self, activating the immune response. The entry of the pathogen binds to specific receptors on B cells, a type of white blood cell. This binding activates the B cells, leading them to proliferate and differentiate into plasma cells. Plasma cells then produce antibodies that specifically target the antigens, marking the pathogens for destruction by other immune cells.