Control Flashcards
What are reflexes
Automatic response to an external signal
What is kinesis
Change in activity rate in response to a stimulus
Why do woodlice not move away from light
Cannot sense gradient - can’t see light to turn away from it
What is taxis
Directional movement towards or away from stimulus
Why do marine plankton alternate between positive and negative phototaxis
Needs to be on sea bed
Detects light near top so uses negative phototaxis to sink
Not right conditions on bottom so uses positive phototaxis to enter water column again
Repeats
How does the body knows it’s hungry
Stretch receptors in the stomach tell the brain it’s empty
Describe the nervous system of a star fish
No brain
Ring of nerves with nerves radiating into limbs. Nerves in limbs pass on electrical impulses to ring of nerves in middle
Describe the nervous system of worms and leaches
Ganglia - bundles of nerves
What makes up the central nervous system
Brain
Spinal chord
What makes up the peripheral nervous system
Cranial nerves
Ganglia outside CNS
Spinal nerves
Why is the brain folded
Increase surface area
What are the two parts of the brain
Primary motor cortex
Primary somatosensory cortex
Where do connection of neurones occur on the brain and why
On the surface of the brain
Increase surface area
What do hormones do
Provide proximate control
Influence development
Species name of the blue headed wrasse
Thalassoma bifasciatum
