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.
Plate boundaries are the edges where two points meet.
Answer:
During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. These sugar molecules are the basis for more complex molecules made by the photosynthetic cell, such as glucose.
Explanation:
"Ammonification" is NOT a process that drives the carbon cycle.
<u>Option: B</u>
<u>Explanation:</u>
The organisms circulate carbon-di-oxide in carbon cycle by going through respiration, decomposition, sedimentation, and photosynthesis process but not ammonification. Basically the actual source of nitrogen is agricultural, when a plant or animal passes or an animal disperses waste.
In the remains, bacteria or fungi turn the organic nitrogen back into ammonium, a cycle called ammonisation or mineralisation. Then the micro-organisms generate metabolically required energy from organic nitrogen oxidation into ammonium. Ammonium is then essential for assimilation and absorption into amino acids or for use in other metabolic applications.
