<span>it has at least two effects: disrupting oxygen delivery and protecting against malaria </span><span />
Answer:
Mutations caused by enviromental factors.
Explanation:
All the other answers choices have to do with more than one gene.
The esophageal sphincter closes after a bolus has been swallowed and enters the stomach.
<h3>What is the esophageal sphincter?</h3>
The esophageal sphincter is a sphincter that separates the esophagus from the stomach. The muscle attached thereto pushes the bolus down the stomach.
Hence, esophageal sphincter closes after a bolus has been swallowed and enters the stomach. This sphincter is essential to prevent the contents of the stomach reentering the esophagus.
Learn more about the stomach: brainly.com/question/8836658
Answer:
Tetrahedron Structure The chemical structure of silica forms a tetrahedron. It consists of a central silicon atom surrounded by four oxygen atoms, with which the central atom bonds. The geometric figure drawn around this arrangement has four sides, each side being an equilateral triangle—a tetrahedron.
Explanation: