Answer:
I, II, III
Explanation:
A threshold stimulus is a stimulus that is capable to produce a response in excitable tissues such as neurons and muscle fibers. At threshold potential, the outward movement of K+ and inward movement of Na+ become equal to each other. When the potential exceeds the threshold potential, more and more Na+ enter the cell to depolarize it and to allow the opening of Na+ channels. Therefore, to fire an action potential, the threshold must be exceeded.
Conduction of action potential is all or none phenomenon which means that either it occurs or it does not occur. As an impulse is passed by each successive part of an exon, it enters the refractory period during which there is no conduction of nerve impulse. It ensures the one-way conduction of impulse from the cell body to the axon terminal only.
The answer is a compound leaf!! Hope this helps ;)
Answer:Primary succession occurs on land that is new and has never had a flora and fauna example: glacier retreats, lava flows. Secondary succession occurs on land that has been cleared example: by fire, of flora and fauna, but which still has viable seeds and spores in the soil.
B. is a long crack, which releases lava, steam, and gases
Explanation:
A fissure is a long crack which releases lava, steam and gases into the environment. Fissures are mostly associated with volcanic bodies.
A volcano is an igneous structure by which lava erupts on the earth surface.
- most volcanoes have fissures through which they release materials into the environment.
- these features are usually permeating cracks into the deeper magmatic body.
- they often times acts as conduit for magma to reach the surface.
- in a volcanic terrain, fissures can provide good clues to the occurrence of an eruption.
learn more:
volcanic bodies brainly.com/question/5055821
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