Ais a gas-filled sac that regulates buoyancy and depth.

Which of the following is the best definition of aerobic respiration? o a. the cellular process that releases energy by breaking down glucose o b. physical activity that involves the repeated motion of large muscle groups o c. physical activity that increases heart rate and breathing rate o d. the cellular process that converts solar energy to chemical energy

Vessels draining the myocardium of the heart, open primarily ,into which chamber?

Identify two examples of chemical reactions that you have encountered during the last week. identify an exothermic and endothermic reaction. explain.