The three mechanisms which regulate the heart are endocrine, cardiovascular and Sinoatrial nodes.
The endocrine system consists of the glands and hormones of the human body. The cardiovascular system is the organ system which is responsible for the circulation of the blood around the body and the oxygenation of the body's tissues. The sinoatrial node (SA node) generates the electrical impulses and is considered the natural pacemaker of the heart.
Answer: digestive is the correct answer
According to Charles Darwin's theory of Evolution by natural selection, organisms that possess heritable traits that enable them to better adapt to their environment compared with other members of their species will be more likely to survive, reproduce, and pass more of their genes on to the next generation.
(n.d.). Retrieved from http://www.nas.edu/evolution/Definitions.html
One word answer:Adaptation:
It proves that living organisms MUST come from other living organisms, an egg couldn't magically appear in a pile of chicken seed, a hen would have had to lay the egg first, just as a nucleoulus makes ribosomes so the cell can have proteins, the proteins don't just materialize within the organism.
The sugar formed when two simple sugars are combined by glycosidic linkage.