So to sum up, when matter is transitioning from solid to liquid (melting) or liquid to solid (freezing<span>), its </span>temperature<span> is fixed at the </span>melting/freezing<span> point, which is the </span><span>same temperature</span>
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt). Groundwater can be extracted using a water well.
Protozoans, bacteria, fungi... viruses are not organisms
<span>Stability is often preceded by a "crash" since the growing population eventually is too large for the available resources.
Stability refers to population stability. The growth of the population may destabilize the population stability.
The population size may become so large, so there will be no enough resources for species to survive. </span>
The correct answer is: Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate (junctional folds of the sarcolemma) and sodium enters the cell.
Action potential travels through the membrane of the presynaptic cell causing the voltage-gated channels permeable to calcium ions to open. Ca2+ flow through the presynaptic membrane and increase the Ca concentration in the cell which will activate proteins attached to vesicles that contain a neurotransmitter (e.g. acetylcholine). Vesicles fuse with the membrane of the presynaptic cell, thereby release their contents into the synaptic cleft-space between the membranes of the pre- and postsynaptic cells. Neurotransmitter ACh binds to its receptors on the postsynaptic membrane and its binding causes depolarization of the target cell (muscle cell). Depolarization occurs because sodium enters the cell as a result of neurotransmitter receptor binding.