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The human body is a very complex and interesting thing and we as humans are made up of cells. Each cell in the human body has its own specific role. A cell can be found in all organisms including humans. The cell theory states a cell is the basic unit of life. There are both unicellular and multiceullar organisms.

Although there are different types of cells, most cells have the same components. A cell consists of a nucleus and cytoplasm and is contained within the cell membrane, which regulates what passes in and out. The nucleus contains chromosomes, which are the cell's genetic material, and a nucleolus, which produces ribosome. The cytoplasm consists of a fluid material and organelles, which could be considered the cell's organs. These are just a few characteristics all cells share

New cells can only reproduce from preexisting cells. Cells repeatedly divide to make more cells for growth and repair. When each cell is divided it contains a complete set of DNA. Before a cell divides the instructions are copied so that each of the two new cells gets all information needed to carry on with its role.

Cells vary in size they are extremely small due to the fact that they have to travel through blood vessels and such. Most cells cannot be seen by the naked eye. Cells are the smallest structure capable of basic life processes, such as taking in nutrients, expelling waste, and reproducing. The average sized human cell can fit on the head of a pin.

The body is composed of many different types of cells, each with its own structure and function. Some, such as white blood cells, move freely, unattached to other cells. Others, such as muscle cells, are firmly attached one to another. Some cells, such as skin cells, divide and reproduce quickly. Cells hold many different roles in the human body for example, some cells in the breast produce milk, some in the pancreas produce insulin
, some in the...