Regulation in Lower Organisms

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Regulation in Lower Organisms
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Aim How does regulation occur in lower
organisms?
I. Regulation in Lower Organisms
A. Ameba shows coordinated movements in
enveloping food particles, locomotion, and
avoiding harmful substances.
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B. Paramecium have minute fibers that transmit
impulses to the cilia that helps regulate
locomotion and ingestion of food.
cilia
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C. Hydra has a nerve net.

1. Controls activities of the hydra
2. Has no CNS and impulses travel in any direction
   over the net.

Nerve net
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D. Earthworm
1. Brain is a mass of ganglia (neurons grouped
together)
2. Ventral Nerve cord main nerve that is
connected to the brain and runs along the
length of the animal.
3. Nerve branches smaller nerves branch off
ventral nerve cord to all parts of the body.
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E. Grasshopper
1. Has brain (ganglia) similar to the earthworm
2. Ventral nerve cord
3. Sensory organs

1. Eye
2. Tympanum membrane (sound)
3. Antennae for feeling