<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:
People feel fireworks before hearing it because light travels faster than sound.
Explanation:
We always see the colors of the fireworks before hearing their defeaning sounds. This is because light travels faster than sound, so we can see the light before hearing the sound. An example of this is seeing lightning before hearing thunder. When lightning strikes, the air around it moves very quickly, causing vibrations.
<em>Hope this helps!</em>
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<em>xoxo,</em>
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<em>cafeology</em>
Answer:
Nucleus
the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
Nucleolus
a small dense spherical structure in the nucleus of a cell during interphase.
If an anthropod does not change it's form except for increasing its size, this change would be considered an incomplete metamorphosis.
because fossil fuels take forever to be created hope this helps
