Inside the nucleus of every cell is deoxyribonucleic acid (DNA), a tightly coiled molecule that contains genes. Genes determine all the features found in living things, such as eye color, the pattern on a butterfly’s wings, or the color of a flower’s petals.
A mitochondrion is a tiny, sausage-shaped structure found inside a cell. A mitochondrion makes energy for the cell.
Red Blood Cells
Red blood cells carry oxygen to cells and tissues throughout the body. Red blood cells can bend to squeeze through the tiniest blood vessels and deliver oxygen wherever it is needed.
Nerve cells are the workers of the nervous system. Found throughout the body, nerve cells send electrical signals that direct all of your body’s activities, including thinking, breathing, and moving.
Most cells divide at some time during their lives. Organisms rely on cell division for reproduction, growth, and repair and replacement of damaged or worn-out cells.