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The human immune system uses several different types of cells to eliminate virally infected cells - VCE - SSCE Biology - Question 5 - 2020 - Paper 1
Question 5
The human immune system uses several different types of cells to eliminate virally infected cells. Name one of these cells and outline how it eliminates virally inf... show full transcript
Worked Solution & Example Answer:The human immune system uses several different types of cells to eliminate virally infected cells - VCE - SSCE Biology - Question 5 - 2020 - Paper 1
Step 1
Name one of these cells and outline how it eliminates virally infected cells.
Answer
One cell type involved in eliminating virally infected cells is the Cytotoxic T cell (CD8+ T cell).
Cytotoxic T cells recognize and bind to viral antigens presented on the surface of infected cells via Major Histocompatibility Complex (MHC) class I molecules. Upon recognition, these cells release cytokines that activate other immune cells and induce apoptosis (programmed cell death) in the infected cells, effectively clearing the infection.
Step 2
State the role played by the lymphatic system in an immune response.
Answer
The lymphatic system plays a crucial role in an immune response by providing a site for the activation and proliferation of lymphocytes. It transports antigens and immune cells throughout the body, facilitating the detection of infections and allowing for the efficient circulation of immune cells such as B cells and T cells within the lymph nodes.
Step 3
Describe the sequence of events that occurs in the secondary lymphoid tissue that results in the production of antibodies.
Answer
The sequence of events in secondary lymphoid tissue that leads to antibody production involves the following steps:
- An antigen presenting cell (APC) presents the antigen to T helper cells.
- The T helper cells are activated upon recognition of the antigen.
- Activated T helper cells then stimulate B cells by providing necessary signals.
- The B cell undergoes clonal expansion, proliferating into multiple identical B cells that are specific to the antigen.
- Subsequently, the plasma cells produced by this clonal expansion secrete antibodies specific to the antigen.