1. Action potential reaches the axon terminal and depolarizes it.
2. Depolarization opens voltage-gated calcium channels, enabling influx of Ca into the neuron.
3. Calcium binds to specialized proteins on vesicles (containing pre-made acetylcholine) and triggers them to fuse with the neuron membrane at the synapse.
4. Exocytosis of acetylcholine into the synaptic cleft occurs.
5. Acetylcholine diffuses across the synapse and binds to nicotinic receptors on the end plate of the myocyte.
6. Activated nicotinic receptors, themselves ion channels, cause cation influx into the myocyte and generate an end plate potential. This eventually gives rise to the full depolarization within the myocyte that enables contraction.
<span>Both protexts the organisms' organelles which are inside the cell.
Animal Cell: Cell Membrane
Plant Cell: Cell Wall
Cell
wall is present only in plants, it is not found in all organisms.
Compared to the cell membrane, a cell wall is thick and has a rigid
structure. You can see it in a light microscope, because it is visible.
It serves as the protective cover that surrounds the plasma membrane in a
plant cell. Cell membrane is composed of lipids. Cell walls can be made
up of cellulose or peptidoglycan or chitin.<span> </span></span>
Answer:
I am not sure but I think option d is correct
<span>Nearly all nutrients present in tropical rainforest forests are contained in the (soil)</span>