Well there are infact 2 walls. There is the atrial septum which separates right and left atriums. And there is the ventricular septum which separates the right and left ventricles.
I'm not quite sure if if it's asking you for two or one answer, but maybe writing both shall help.
c. illustrate is your answer
<em>Answer: Mitochondria are found in all body cells, with the exception of a few. There are usually multiple mitochondria found in one cell, depending upon the function of that type of cell. Mitochondria are located in the cytoplasm of cells along with other organelles of the cell.</em>
<span>the radius of the sun is 432,450 miles (696,000 km)</span>