What are antibodies?
Antibodies are specific proteins released by plasma cells that attach to pathogenic antigens.
What are B memory cells?
Cells that remain in the blood for a long time and provide long-term immunity.
What is clonal expansion?
An increase in the number of cells by mitotic cell division.
What are interleukins?
Signalling molecules used to communicate between different white blood cells.
What are plasma cells?
Plasma cells are derived from B lymphocytes and manufacture and release antibodies.
What are T helper cells?
T helper cells release signalling molecules (cytokines) that stimulate the immune response.
What are T killer cells?
T killer cells attack and destroy body cells infected by a pathogen.
What are T memory cells?
T memory cells remain in the blood for a long time and provide long-term immunity.
What are T regulator cells?
T regulator cells inhibit or shut down the immune response after the pathogen has been removed and help prevent autoimmunity.
What cells are involved in the specific immune response?
B lymphocytes (B cells) and T lymphocytes (T cells). These are white blood cells with a large nucleus and specialised receptors on their plasma membranes.
What is produced during the specific immune response?
Antibodies are produced, which neutralise foreign antigens.
How does the specific immune response provide long-term protection?
By producing memory cells (B and T memory cells) that circulate in the body for years, providing immunological memory.
What are the four types of T cells produced during the immune response?
● T helper cells (Th)
● T killer cells (Ti)
● T memory cells (Tm)
● T regulator cells
What is the role of T helper cells?
They release cytokines that:
● Stimulate B cells to develop
● Stimulate phagocytosis by phagocytes
What is the role of T killer cells?
They attack and kill host body cells displaying foreign antigens.
What is the role of T memory cells?
They provide long-term immunity by remaining in circulation.
What is the role of T regulator cells?
They shut down the immune response after pathogen removal and help prevent autoimmunity.
What two types of cells do B lymphocytes develop into?
● Plasma cells (produce antibodies)
● B memory cells (provide long-term immunity)
How are lymphocytes activated?
Pathogens have specific antigens that must bind to lymphocytes carrying complementary receptor molecules on their plasma membranes.
Why are lymphocyte receptors specific?
The receptor proteins have shapes complementary to the antigen’s shape.
How does antigen contact occur?
● Directly when pathogens enter lymph nodes
● Via antigen-presenting cells
What happens after lymphocytes are activated?
They undergo clonal expansion - increasing in number by mitosis to become effective.
Do lymphocytes directly manufacture antibodies when first activated?
No. Selected clones differentiate into specialised cells, such as plasma cells, which then produce antibodies.
Why is cell signalling necessary in the immune response?
The response involves coordinated action of many cell types, so they must communicate effectively.
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4.1.1 Organisms That Cause Disease32
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4.1.2 Transmission Of Pathogens47
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4.1.3 Plant Defences Against Pathogens27
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4.1.4 Primary Defences Against Disease39
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4.1.5 Secondary Non-Specific Defences28
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4.1.6 The Specific Immune Response35
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4.1.7 Antibodies26
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4.1.8 Vaccination23
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4.1.9 Development And Use Of Drugs22
