Answer:
A presynaptic neuron knows when and how much of a certain neurotransmitter it has to release into the synapse by the frequency of the action potential.
Explanation:
Two nuerons connect to each other through synapse. When an action potential, or nerve impulse, arrives at the axon terminal, it activates voltage-gated calcium channels in the cell membrane, then the calcium which is present in hi highconcentration outside the neuron than inside, rushes into the cell. The Calcium then allows synaptic vesicles to fuse with the axon terminal membrane, releasing neurotransmitter into the synaptic cleft.
The nuerotransmitter than binds to the receptors at the post-synaptic cleft and causes the opening or closing of the channels, hence, depolarizing or hyperpolarizing the cells.This can produce a change in the membrane potential—voltage across the membrane of the receiving cell.
Answer:
They protect you against illness and disease. Think of white blood cells as your immunity cells. In a sense, they are always at war. They flow through your bloodstream to fight viruses, bacteria, and other foreign invaders that threaten your health.
Temperate evergreen forests, coniferous, broadleaf, and mixed, are found largely in the temperate mid-latitudes of North America, Siberia, Canada, Australia, Africa, Scandinavia, Indonesia, Malaysia, Amazon and Orinoco basins of South America, Himalayas and western ghats of India and Andaman and the Nicobar Islands.
A commensal bacterium does not infect its host, which is option D. Details about commensalism can be found below.
<h3>What is commensalism?</h3>
Commensalism is a kind of relationship that involves the sharing of the same environment by two organisms where one species benefits and the other is unaffected.
For example, barnacles on whales is a commensalistic relationship.
According to this question, a commensal bacterium will not affect or harm it's host by infect it neither will it benefit its host.
Learn more about commensalism at: brainly.com/question/14224704
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They get different weather patterns than a jungle, flatland, prairie, or taiga. it's just it's own thing.