The cell cycle consists of three phases: the interphase (G1, S, G2) the mitotic (M) phase, and cytokinesis. <span>The first checkpoint of the cell cycle is G1 checkpoint which is between G1 and S phase when cell checks its size, nutrients, molecular signals, DNA integrity. The second checkpoint is G2, just before the mitotic phase, when cell checks DNA integrity and DNA replication. Those two checkpoints are the ones before division, other like M checkpoint is during the mitosis.</span>
Skeletal muscle fibers are classified based on "how does it regenerates ATP" and "how fast does it contract compared to others". Compared to the other types of fibers slow oxidative fibers are known to produce low power contraction and these contractions persists over long time periods compared to the fast oxidative and fast glycoltic fiber types.
Pollution can effect the food chain and the food web In many ways. The first of wich is it can kill off animals. A good example of this is marine life.
