Answer:
E. that area of the membrane is in the absolutely refractory period.
Explanation:
Refractory period is a period during which neuron cell cannot be stimulated (depolarized). This is why the action potential can only travel in one direction from the neuron body towards axon.
Refractory period occurs because of the inactivation of voltage-gated sodium channels (while action potential is at its peak) which cannot be open for a certain period of time. and membrane cannot be depolarized.
3. naturally occurring
4. fossilized plants or air bubbles ( probably the plants tho)
5. increased
6. the green house effect occurs naturally, it is being polluted both naturally and unnaturally, the unnatural pollution is contaminating our 'greenhouse" and that is horrible.<span />
When the earth is between the moon and the sun
Answer:
C. Spiral Galaxies is the answer
In
cell-cell contact , signals pass through a cell junction from one cell to adjacent cells.
Membrane-bound signals bind to receptors on adjacent cells in the process of
paracrine signalling.
An example of
autocrine signalling is when cells release signals that affect themselves and nearby target cells.
In
synaptic signalling cells release signals that affect nearby target cells. Cells release signals that travel long distances to affect target cells during
endocrine signalling.
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