The pyloric sphincter is compose of smooth muscle and is located between the pylorus in the stomach and duodenum of the small intestine. In digestion, it serves as a valve controlling the flow of food thus it prevents the contents of small intestine backing up into the stomach.
Natural selection can cause speciation, which increases the biodiversity of an ecosystem. Several bacterial colonies are placed on a petri dish that contains agar with antibiotics. After 24 hours, ninety percent of the original bacteria die, but the remaining ten percent survive and later reproduce.
<span>B. The enzyme amylase was saturated, as all its active sites were occupied by substrate starch.
Each enzyme molecule has an active site in which it binds to a substrate to complete the enzyme-substrate complex. This means that there has to be a balance of enzyme molecules to substrate molecules. </span>