<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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A. can cats learn to sit down on command
Answer:
Diamonds are extremely durable and graphite (pencil lead) is very fragile.
Explanation:
Answer:
There are two paths of a drop of blood leaving the human heart. First, the deoxygenated blood leaves the heart and second, oxygenated blood leaves the heart,
Explanation:
Deoxygenated blood leaves the heart through an artery called pulmonary artery which take this blood to the lungs. After that, oxygenated blood carries from lungs to the heart through pulmonary vein. The oxygenated blood in the heart leaves the heart through aorta and distribute this blood in all parts of the body.
I am pretty sure it is D. confucius lived during the Zhou dynasty and from what i have read the dynasty sounds pretty peaceful
