It is mostly likely the cell membrane.
The cell membrane is a structure of a cell composed of double layer of lipids and proteins. It surrounds a cell and separates the cytoplasm from its surrounding environment. The cell membrane is selectively permeable (semi-permeable), which means that it only lets certain molecules enter and exit. It can also control the amount of some substances that go into or out of the cell.
Over long periods of time, living things have gradually altered as the conditions around them change. A species' strongest traits are passed from one generation to the next. This is what evolution is, the process of gradual change.
A muscle stimulated<span> at high-frequency with some short relaxation time between ... smooth </span>muscle cells<span>... voluntary via axonal endings of the somatic </span>nervous<span> system .... </span>Which of the following<span> does NOT occur during skeletal </span>muscle contraction<span>? .... </span>true<span>. the space between he neuron and the </span>muscle<span> is the</span>axon<span> terminal. false.</span>
B temperature and precipitation