Multicellular animals can control activities of different tissues and organs in their bodies, by detecting change in the external or interval environment; detect a stimulus so a response can be brought about by an effector
By responding to external and internal stimuli, animals increase chance of survival by avoiding harmful conditions and maintain optimal conditions for metabolism
Internal Environment: Conditions inside the body and External Environment: Conditions outside of the body
Stimulus: Environmental change, causing a Response: Change in behaviour or physiology, by an Effector: Body part causing the response (e.g. muscle or gland)
Most animals and plants are multicellular and complex with different organs and tissues carrying out specific functions; it’s vital the activities of different cells, tissues and organs are coordinated
Systems responsible for co-ordination are nervous system and endocrine system; multicellular plants have no nervous system but their cells produce chemicals with hormone type effects called plantgrowthregulators
Coordination relies on cellsignalling, this is the communication between cells so that they work together to bring about a response
Efficient communication system in animals: Cover whole organism, allow for cellsignalling, specific and rapid communication and result in both short and long term responses
