Cells and Cell Division

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Cells and Cell Division

Publisher: North Western University
Number Of Pages: 23
Publication Date: 2003
Binding: pdf

Cell division is a complex process but with a little research it can certainly be understood. Cell division is important because it is the basis for all life. As cells divide, they create a new organism. After growth, cell division helps repair and take care of organisms.

excerpt

Cells and Cell Division
Almost everything in the world is made up of smaller
things. Houses are built out of individual bricks and
pieces of wood. Cars are built out of pieces of metal,
plastic, and rubber. Think about your favorite toy.
What parts make up your favorite toy?


The Cell Theory
One very important similarity among all living things is that they are
made of cells, the smallest units of life. In 1838, two biologists,
Schleiden and Schwann, studied many cells and made some conclusions.
From their observations they developed what is known as the Cell
Theory. Since then, this theory has been central to our understanding of
biology. This theory states that:


1. All life forms are made from one or more cells. Some
organisms, like bacteria or paramecium, are only one cell big. These are
called unicellular organisms (uni=one). Other organisms are
multicellular: that means they are made up of more than one cell
(multi=more than one). For example, the human body consists of
billions of cells!


2. Cells only arise from pre-existing cells. A cell can make copies
of everything it has inside it, then divide itself in two, making two new
cells. This process is called mitosis, or cell division. In this way,
organisms can keep growing or replace damaged or old cells. For
example, the formation of new cells is what allows your body to grow,