Every cell in the body goes through a life cycle. Cells grow and divide to replace cells that are lost because of normal wear and tear or injury. Different cells grow and die at different rates. Some cells, such as epithelial<span>epithelialA thin layer of epithelial cells that makes up the outer surfaces of the body (the skin) and lines hollow organs, glands and all passages of the respiratory, digestive, reproductive and urinary systems.</span> cells, reproduce quickly. Other cells, like nerve cells, grow slowly. Both normal cells and cancer cells go through a sequence of steps, or phases, when they form new cells. This is called the cell cycle.
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Cellulose. Our bodies as humans lack enzymes to break the cellulose down.
B) the amount of available resources
A because the vesicles transport materials and nutrients around the body.
In photosynthesis, an electron carrier of the light cycles is the nicotinamide adenine dinucleotide phosphate or NADP. This is the oxidized form, because the reduced form of this carrier has the extra H (NADPH). This is somehow related to the electron carrier called nicotinamide adenine dinucleotide or NAD (minus the phosphate).
