explanation; During exercise there is an increase in physical activity and muscle cells respire more than they do when the body is at rest. The heart rate increases during exercise. The rate and depth of breathing increases - this makes sure that more oxygen is absorbed into the blood, and more carbon dioxide is removed from it.
<u>A human liver cell would have a different size and shape from a human muscle cell because they perform different functions in the body.</u>
<em>The shape a cell would assume and its size depends on the function the cell performs. The functions of the liver in the body of humans differ greatly from the functions of muscles. While the former helps in detoxification, deamination, digestion, etc., the latter helps in support, movement, etc. </em>