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...
The Process of Active Transport & Co-transport Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher c...
Required Practical: Investing Water Potential Using Calibration Curves It is possible to investigate the effects of immersing plant tissue in solutions of different water potentials and then...
