What is a stimuli
Changes that can be detected
What is a receptors
Detect the changes
What is the effectors
Bring about the response
What do these detect
Ears
Eyes
Tongue
Nose
Skin
Sound
Light
Chemicals
Chemical
Pressure and temp
What is the nervous system
It consists of the spinal cord and brain. This is called the central nervous system
What is the order of the reflex arc
Stimuli, receptor cells (electrical impulses, sensory neurons, relay neurons, motor neurons, effector (muscle or gland)
Term continuous variation
A feature changes gradually over a value
E.g weight, height
Term discontinuous variation
Fit into one group or another limite number of possibilites
Term mutation
A change in the dna sequence
Examples that could cause mutations
Exposure to ionising radiation such as skin cancer caused by exposure to ultraviolet light from the sun
Term survival of the fittest
Individual best suited will survive over other individuals
Term natural selection
Process where advantages gene are posted on to offspring
Scientist responsible for evolution
Charles Darwin
Three things to describe the reflex arc
Protective
Automatic
Fast
What is homeostasis
Maintaining a constant internal environment
What is the function of the skin
Protects from infection
Keeps body at right temp
Covered in receptors so we can feel things
