Survival and Response Flashcards
What is a stimulus?
A change in an organisms internal/external environment, causing a response.
What is a receptor?
Detects the change (stimulus), it is specific to 1 type of stimulus.
What is a sensory neurone?
Passes electrical impulse from receptor to coordinator.
What is a coordinator?
Formulates a response.
What is a motor neurone?
Passes electrical impulse from coordinator to effector.
What is an effector?
Produces a response, e.g. muscle contraction or gland releasing hormone.
What are the characteristics of simple reflex actions?
- Involuntary
- Protect from danger
- Simple reflexes are specific; one stimulus = one response
- Fewer neurones, fewer synapses, faster response
- Doesn’t involve the conscious part of the brain
What is behaviour?
Action that alters the relationship between an organism and its environment.
What is innate behaviour?
Genetically determined behaviour so environment has no impact, passed onto offspring.
What is kinesis?
The non-directional response to a stimulus. The response is a change in the speed of random movement.
What is taxis?
‘Directional’ orientation response.
What is tropism?
Directional growth responses in plants determined by the direction of the external stimulus.
What does IAA stand for?
Indoleacetic acid.
How does IAA effect cell elongation?
IAA promotes cell elongation in shoots and inhibits cell elongation in roots.
Does IAA diffuse to the light side or the shaded side?
The shaded side.
