<em>A plasma membrane is the cellular structure that makes it possible for a cell to differ structurally and biochemically from its surroundings. </em>
<u>Explanation:</u>
<em>Plasma membrane</em> is the surrounding of all the cells. The function of plasma membrane in a cell is to regulate the incoming and outgoing elements from the cell.
<em>Phospholipid bilayer</em> is the main composition of plasma membrane. It makes the cell different from each other structurally as well as makes the cell different in <em>chemical composition </em>too.
An environment high in carbon dioxide and high in oxygen induce oxygen to bind to hemoglobin. Another factors are an environment under high pressure and an environment under low pressure.