Investigating Variables that Affect Heart Rate There are a wide range of factors that influence the heart rate of an organism Experiments can be designed to investigate the effect of a named...
Heart Action: Initiation & Control Control of the basic heartbeat is myogenic, which means the heart will beat without any external stimulus This intrinsic rhythm means the heart beats a...
Edexcel IGCSE Biology 复习笔记 2.5.1 Photosynthesis Photosynthesis Theory Photosynthesis is an endothermic reaction in which energy from sunlight is transferred to the chloroplasts in green ...
The Human Retina The eye is a sense organ containing receptors sensitive to light intensity and colour Receptors are groups of specialised cells that can generate an electrical impulse in a ...
Edexcel IGCSE Biology 复习笔记 2.4.5 Active Transport Active Transport Theory Active transport is: The movement of particles through a cell membrane from a region of lower concentrati...
Investigating Touch and Temperature Receptors on Skin Within the human skin, there are many temperature and touch receptors that enable humans to interpret and respond to their environment E...
Edexcel IGCSE Biology 复习笔记 2.4.4 Practical: Osmosis Practical: Factors that Influence Osmosis Osmosis is the diffusion of water molecules from a dilute solution (high concentration of water) to...
Establishment of a Generator Potential When Pacinian corpuscles are stimulated by pressure on the skin this leads to the establishment of a generator potential This happens due to the moveme...
Edexcel IGCSE Biology 复习笔记 2.4.3 Osmosis Osmosis Theory All cells are surrounded by a cell membrane which is partially permeable Water can move in and out of cells by osmosis Osmosis is ...
