Mass Transport The need for a circulatory system The cells of all living organisms need a constant supply of?reactants for metabolism, e.g. oxygen and glucose Single celled organisms can gain oxyge...
The Process of Digestion Digestion is a process in which relatively?large, insoluble biological molecules?in food (such as starch, proteins)?are hydrolysed?into?smaller, soluble molecules?that can ...
The Human Gas Exchange System: Structure Gas exchange takes place in the human thorax. This is a collection of organs and tissues in the chest cavity The main structures of the human gas exc...
Surface Area to Volume Ratio Surface area?and?volume?are both very important factors in the?exchange of materials?in organisms The surface area refers to the?total area of the organism that is expo...
Vaccines A?vaccine?is a suspension of?antigens?that are intentionally put into the body to induce?artificial active immunity. A specific immune response where?antibodies?are released by?plasma cell...
Cell Recognition Our bodies have?several defence mechanisms?against?pathogens. These include: Preventing?the?entry?of pathogens by a variety of?physical?and?chemical?defences, such as the skin, muc...
The Fluid Mosaic Model of Membranes Membranes are vital structures found in all cells The cell surface membrane creates an enclosed space separating the internal cell environment from the external ...
Interphase Within multicellular organisms,?not all cells retain the ability to divide Eukaryotic cells that do retain the ability to divide show a cell cycle Mitosis?is part of a?precisely controll...
The Principles & Limitations of Microscopy Microscopes?can be used to analyse?cell components?and observe?organelles Magnification?and?resolution?are two scientific terms that are very importan...
