Transcript Homeostasis - This is Worley Science

Homeostasis
A state of
balance
in an organism
Whoa
Definition of Homeostasis
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Homeostasis is the ability or tendency
of an organism or cell to maintain
internal equilibrium by reacting to
internal stimuli.
Organism is an individual form of life,
such as a plant, animal, bacterium,
protist, or fungus.
Response to Internal Stimuli
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Internal Stimuli are things that
happen inside an organism that cause
the organism to react.
An organism must return to equilibrium
when confronted by a stimulus.
Equilibrium is a when all the
conditions of a system which are
competing influences are balanced.
Homeostasis Has Three Parts
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Receptor- a sensor that is sensitive to
a particular environmental change or
stimulus.
Control Center- receives and process
the information supplied by the receptor.
Effector- a cell or organ that responds
to the commands of the control center
and whose activity opposes or enhances
the original stimulus.
Homeostasis in Your House!
Two Types of Feedback
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Negative feedback mechanisms consist of
reducing the output or activity of any organ
or system back to its normal range of
functioning.
Ex. Plants growing roots to new water
sources when their current source runs dry.
The Second Kind of
Feedback
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Positive Feedback mechanisms are
designed to accelerate or enhance the
output created by a stimulus.
Ex. Plants produce chlorophyll when
they sense light.
Wilting in Plants
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Wilting is a plant becoming limp
through heat, loss of water, or disease.
The plants response to the stimulus is
to increase Turgor pressure by
accelerating osmosis.