Answer;
-Positive charge
Prior to the arrival of a signal from a presynaptic input, the post-synaptic membrane is polar with a greater relative positive charge to the ECF
Explanation;
-Neurons talk to each other across synapses. In somatic neurons, an action potential arrives at the synapse causing synaptic vesicles to fuse with the presynaptic membrane. The pre-synaptic membrane releases acetyl choline via exocytosis into the extracellular of the synaptic cleft.
-The ACh diffuses across the cleft and binds to the ligand-regulated sodium channels. Activated sodium channels allow a rapid diffusion down its electrochemical gradient towards the ICF. The movement of positive charges to the ICT causes the relative charge across the membrane to become positive on the inner surface.
Answer:
Description below
Explanation:
Alcionaceans (Alcyonacea) is an order of corals that belongs to the subclass Octocorallia, of the Anthozoa class. <em>Soft corals</em> are commonly called, since they do not produce skeletons of calcium carbonate, so they do not contribute to the construction of the reefs, although they inhabit them.
The so-called soft corals and leather or leather corals, mostly meaty in appearance, have microscopic crystals of calcite in their tissues called spicules, whose function is to give consistency to the animal's tissue, in the absence of a skeleton. The shape and distribution of the spicules are the main characteristics used in the identification of genera and species of octocorals.
In addition to soft corals, this order includes gorgonians, which replace the skeleton of hard corals, Scleractinia order, by semi-rigid structures composed of calcite and / or a substance they generate called gorgonin.
Technically A and B, but A is more true, so it is the 'correct' answer.
It should be true due to adaptations. when a bird doesn’t stay for winter weather so it adapts by migrating to the south during the cold weather