AQA A Level Biology复习笔记2.6.4 AIDS
AIDS Symptoms of AIDS Immediately after infection with HIV people often suffer mild flu-like symptoms These symptoms pass and for a period of time infected people might not know they are inf...
AQA A Level Biology复习笔记2.6.3 HIV
HIV Transmission of HIV Human Immunodeficiency Virus is a retrovirus The HIV virus is not transmitted by a vector (unlike in malaria) The virus is unable to survive outside of the human body...
AQA A Level Biology复习笔记2.6.2 Active & Passive Immunity
Types of Immunity Active immunity Active immunity is acquired when an antigen enters the body triggering a specific immune response (antibodies are produced) Active immunity is naturally acq...
AQA A Level Biology复习笔记2.5.10 Plasma & Memory Cells
Plasma & Memory Cells During an immune response, B-lymphocytes form two types of cell: plasma cells and memory cells Memory cells form the basis of immunological memory – the cells can l...
AQA A Level Biology复习笔记2.5.9 Antigen-Antibody Complex
Antigen-Antibody Complex An antigen and its complementary antibody have complementary molecular shapes This means that their molecular structures fit into each other When an antibody ...
AQA A Level Biology复习笔记2.5.8 Antibodies
Antibodies: Structure Structure Antibodies are globular glycoproteins called immunoglobulins Antibodies have a quaternary structure (which is represented as Y-shaped), with two ‘heavy’ (long...
AQA A Level Biology复习笔记2.5.7 The B lymphocyte Response
The B lymphocyte Response B-lymphocytes and the humoral immune response B-lymphocytes (B cells) remain in the bone marrow until they are mature and then spread through the body, concentratin...
AQA A Level Biology复习笔记2.5.6 The Role of Helper T cells
The Role of Helper T cells Activated T-lymphocytes (those that have receptors specific to an antigen) divide by mitosis to increase in number (similar to the clonal selection and clonal expa...
AQA A Level Biology复习笔记2.5.5 The Role of Antigen-Presenting Cells
The Role of Antigen-Presenting Cells T-lymphocytes produce an immune response when they are exposed to a specific antigen T cells will only bind to an antigen if it is present on the surface...
AQA A Level Biology复习笔记2.5.4 The T Lymphocyte Response
The T Lymphocyte Response Lymphocytes are another type of white blood cell They play an important part in the specific immune response They are smaller than phagocytes They have a large nucl...
AQA A Level Biology复习笔记2.5.3 Phagocytosis
Phagocytosis Phagocytes are white blood cells that are produced continuously in the bone marrow They are stored in the bone marrow before being distributed around the body in the blood They ...
AQA A Level Biology复习笔记2.5.2 Antigens
Antigens Every cell in the human body has markers that identify it Microorganisms (both pathogenic and non-pathogenic), such as bacteria and viruses, also have their own unique markers These...
