The graphic represents the different stages of the cell cycle. Specific genes within the DNA, called inhibitors, stop the cell c
ycle in G1 phase. This process helps to keep the DNA unaltered and the cells dividing at the correct rate. Certain chemicals in our environment may result in mutations of cells' DNA that in turn prevent the inhibitors from halting the cell cycle.
Blood vessels contain smooth muscle in their walls. Cardiac muscle is heart muscle specifically. Skeletal muscle is muscle that forms the voluntary muscles.
