<span>Facts and data are objective, while and opinion is subjective.</span>
Enzymes belong in the category of proteins
Answer: proteins
The atria and ventricles work together, alternately contracting and relaxing to pump blood through your heart. ... The electrical activity spreads through the walls of the atria and causes them to contract. This forces blood into the ventricles. The SA node sets the rate and rhythm of your heartbeat.
Typically, an organism has to have resources such as a food source, water source and some type of shelter in order to survive. For example, a bird needs to build a nest for a shelter, they have to have a water supply and a food supply of bugs or berries depending on the type of bird.
