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...
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...
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...
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...
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 ...
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...
Required Practical: Factors Affecting Membrane Permeability The?permeability?of?cell membranes?is affected by different?factors?or conditions, such as: Temperature Solvent concentration &nbs...
Explaining Adaptations in Specialised Cells Specialised cells for diffusion Root hair cells?and?epithelial cells of the small intestine?are examples of cells that are?adapted?for the rapid t...
Adaptations for Rapid Transport The rate at which?diffusion?(including both?simple?diffusion and?facilitated?diffusion) occurs across external and internal cell membranes?varies Some cells a...
