a.Parasite because it is a living thing.
Cardiac Conduction System is a group of specialized cardiac muscle cells in the walls of the heart that send signal to the heart muscles causing it to contract.
Answer:
The digestive system!
Explanation:
The digestive system is made up of the digestive tract - a series of hollow organs joined in a long, twisting tube from the mouth to the anus - and other organs that help the body break down and absorb food.
Organs that make up the digestive tract are the mouth, esophagus, stomach, small intestine, large intestine - also called the colon - rectum, and anus.
Heat energy is the energy that is lost