Coordination Flashcards
Define homeostasis
Maintaining a constant internal environment
What are the three key components of a co-ordinated response
Stimulus, Effector and Receptor
Stimulus
Receptor function
Detects the stimulus
Effector function
Muscle or Gland which carries out a response e.g shivering
Examples of homeostasis
- Maintaining core body temperature (37°C)- enzymes
- Maintaining blood-glucose levels
What is it called when plants grow in response to light?
phototropism
Why do plants need phototropisms?
To ensure their leaves can absorb light for photosynthesis
What is it called when plants grow in response to gravity?
geotropism
Why do plants need geotropisms?
To ensure their shoots grow upwards and their roots grow downwards
What is a positive tropism?
Growth towards the stimulus
What is a negative tropism?
Growth away from the stimulus
Why do roots grow away from light? (negative geo)
To anchor the plant and absorb water and minerals from the soil.
What are hormones in plants called?
auxins
Where is auxin primarily produced in a plant?
In the tips of growing shoots
How does auxin move in a plant?
It diffuses down from the shoot tip to the region where cell division occurs
How does auxin affect cell growth?
Auxin stimulates cells to elongate
How does auxin respond to light coming from one side?
It concentrates on the shaded side of the shoot.
What are the two control systems in humans which respond to stimuli?
- Nervous system
- Endocrine system
How does the** nervous system** send information?
As electrical impulses that travel along neurones at high speeds.
Why is the nervous system important?
It allows rapid responses to stimuli.
What does the nervous system control?
Functions that need instant responses e.g reflex arcs
How does the endocrine system send information?
Through hormones
Hormones function
They transmit information and trigger a response by altering the activity of target organs
