<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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Answer:
The force of friction is reduced between the blocks by adding the dishwashing liquid because the liquid is slippery and this makes it difficult for the two surfaces to contact each other directly. Therefore the blocks slip past each other rather than grinding against each other, producing less friction.
Explanation:
Hope This Helps :P
Differences and similarities between igneous , metamorphic , and sedimentary rocks . sedimentary rocks are formed by weathered sediment using cementation or precipitation on Earth's surface . Metamorphic rocks are formed by changes of pressure and temperature within Earth's surface .
I believe it's the temperature in the core
D. they reproduce by binary fission, is the answer I think