Cells are the tiny building blocks of living things. Each cell has a past called a cell membrane; a thin covering around
the cell. The cell membrane separates the inside parts of the cell from the outside environment, gives the cell its shape, and
controls what goes into and out of it. Located inside a cell is the cytoplasm. Cytoplarm is a jellylike liquid. Inside the cytoplasm
is the cell's control center called the nucleus. The nucleus contains all of the instructions for running the cell. The nucleus is surrounded by the nuclear membrane. The nuclear membrane controls what goes into and comes out of the nucleus.
A cell is able to reproduce by means of splitting. One cell splits into two cells. However before the cell splitis, the nucleus doubles and divides in half so each new call has a copy of the cell's instrunctions.
Look carefully at the diagram of the call below. Notice inside the cytoplasm are vocuoles and mitochondria . Vocuoles are tiny oval structures that store food, water, or wastes. Mitocjondria are shaped like kidney beans. Mitochondria are important parts of a cell because they help change food into energy. The cell uses the energy to do its work.