In the alphabet the basic unit is a letter. In all living things the basic unit is a cell. The smallest living things are singe cells that carry out all of the process of life by themselves. Two of the basic functions of cells are getting energy and getting rid of waste.
When you are getting alittle sleepy during the day what do you do. Many
people grab a candy bar or a soda. Why? One reason is the both contain
sugar. We call this energy. Animals obtain energy by eating things. Anything
that animals eat they digest and convert to sugars. Sugar is the basic
source of energy. Whatever you eat for energy gets converted to sugar.
Now, we also need other things like proteins, fats, vitamins, minerals
and fiber. All of these things that we eat and need are actually used
at the level of a cell. Each cell in your body needs energy and when you
eat foods your body breaks it down int smaller and smaller pieces until
your cells can bring them into your body through the process of osmosis.
This entire process of getting food and breaking it down and your cells
using the energy is called digestion and respiration.
Getting rid of waste
You may have noticed that some of your friends can make unusual body
noises that are odoriferous. That is part of getting rid of waste. Plants
do the same thing but there is no odor. When plants go through the process
of photosynthesis they give off Oxygen as part of their waste. We use
oxygen as we go through the process of respiration and one kind of waste
that we need to get rid of is Carbon dioxide which we breath out. We have
other kinds of waste and it is by products of the cell process that result
in the odoriferous releases from our bodies. Each cell in our body goes
through these process of obtaining energy and releasing waste. Our circlulatory
system helps move those cell wastes so they can be removed by our kidneys
and be removed from our bodies.
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State 7th Grade Integrated Science Core Curriculum Page.
Updated August 27, 2001 by: Glen Westbroek
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