Part 2 Biology Revision Notes for AQA GCSE A/A*
B3.3 Keeping internal conditions constant 3.1 Controlling internal condition Keeping the conditions in the in the body within a narrow range is called homeostasis. Temperature, blood glucose, water and ion content and levels of waste products must all be controlled Waste products that have to be removed include; CO2 (produced by respiration) removed by the lungs urea (produced in the liver when amino acids are broken down) removed by the kidneys and temporarily stored in the bladder Water and ions enter the body when we eat and drink. If the water or ion content in the body is wrong, too much water may move into or out of the cells. This could damage or destroy the cells 3.2 The human kidney