<span>C.
has strong legs for running
</span>
Answer:
The concentration of a substance is the quantity of solute present in a given quantity of solution.
The correct answer is A.
Animal cells do not have a cell wall.
A cell wall is the rigid, outermost covering of plant cells and is made up of cellulose. It is absent in animal cells. The cell wall is visible under a light microscope.
Animal cells are instead covered by a cell membrane. It is made up of lipids, proteins, and small amounts carbohydrates. It is a thin and delicate structure that can only be seen using an electron microscope.
The serotonin binds to a G-protein -coupled receptor and activates a G-subunit . This results in activation of PKA and closing of the potassium channels. This will subsequently decrease the influx of potassium ions into the cell, and lead to depolarization of the cell. This changes the membrane potential of the cell.
Aplysia are sea slugs which fall under the category of mollusks. Serotonin is a hormone which is responsible for the transfer of electrical signals from the brain to different parts. In this particular mollusk, serotonin was studied to find that it is an essential neurotransmitter that is responsible for the maintenance of synaptic plasticity in the neurons. Synaptic plasticity is the feature which is essential for the communication of neurons. This is the modification which occurs at the synapses during the transmission of synapses. Without this activity, the transmission of signals would be impossible.
Learn more about depolarization here-
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