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Outline how any one named feature of the human general defence system works - Leaving Cert Biology - Question 14(a) - 2015
Question 14(a)
Outline how any one named feature of the human general defence system works. Name two organs in the human body that are specific to the immune system. Distinguish ... show full transcript
Worked Solution & Example Answer:Outline how any one named feature of the human general defence system works - Leaving Cert Biology - Question 14(a) - 2015
Step 1
Outline how any one named feature of the human general defence system works.
Answer
One feature of the human general defence system is the skin. The skin acts as a physical barrier that prevents pathogens from entering the body. It has layers that are tough and resilient, providing the first line of defence against infections. Additionally, the skin secretes antimicrobial substances, which help eliminate potential pathogens.
Step 2
Name two organs in the human body that are specific to the immune system.
Answer
Two organs specific to the immune system are the thymus and the spleen. The thymus is responsible for the maturation of T lymphocytes, while the spleen filters blood and helps produce immune responses to infections.
Step 3
Distinguish clearly between an antigen and an antibody.
Answer
An antigen is a foreign particle, such as a virus or bacteria, that triggers an immune response in the body. On the other hand, an antibody is a protein produced by the immune system in response to the presence of an antigen. Antibodies identify and neutralize pathogens.
Step 4
Describe the specific roles of both killer T cells and helper T cells in an immune response.
Answer
Killer T cells play a crucial role in recognizing and eliminating infected cells, cancer cells, or cells that contain foreign agents. They achieve this by producing perforin, which creates pores in the infected cell's membrane, ultimately leading to cell destruction.
Helper T cells, on the other hand, facilitate the immune response by producing signals such as interferon. They help activate B cells, which produce antibodies, and also assist Killer T cells in identifying and responding to antigens.
Step 5
Name the T cells that stop the immune response.
Answer
The T cells that stop the immune response are known as suppressor T cells or regulatory T cells. Their primary function is to dampen the immune response once the threat has been eliminated, preventing the immune system from overreacting and ensuring homeostasis.