You used hypothesis because you made an educated guess without any experiments.
Answer: The circulatory system or cardiovascular system
Explanation: The circulatory system allows the blood to circulate and permits oxygen, carbon dioxide, nutrients, hormones and blood from and to the cells in the body. The system consist of heart, blood and blood vessels. There are five types of blood vessels: the arterioles; the capillaries; here exchange of chemical and water takes place between blood and tissues; the arteries; it carries blood away from the heart; the venules; and the veins, which carries blood from the capillaries back to the heart.
Answer:
The earliest known life-forms are putative fossilized microorganisms, found in hydrothermal vent precipitates, that may have lived as early as 4.28 Gya (billion years ago), relatively soon after the oceans formed 4.41 Gya, and not long after the formation of the Earth 4.54 Gya.
Explanation:
Protein
Proteins are the most versatile
macromolecules in living systems and they play important roles in essentially
all biological processes. Protein makes up the capsid of a virus. The infective
extracellular form of a virus known as a virion contains at
least one unique protein synthesized by specific genes in the nucleic acid of
that virus. In almost all viruses, at least one of these proteins forms a shell
(called a capsid) around the nucleic acid. Certain viruses also have other
proteins internal to the capsid. Some of these proteins act as enzymes during
the synthesis of viral nucleic acids.
Shape of continents.
Location of mountains and fossils. ...
Earthquakes and Volcanoes. ...
Hot Spot Volcanoes.