How do some cells become brain cells and others become skin cells when the DNA IN ALL the cells is exactly the same. In other words, if the instructions are exactly the same how does one cell become a brain cell and another a skin cell?

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what tree

explanation:

phosphorus cycle

explanation:

the phosphorus cycle is the way that compounds of the element phosphorus, an essential nutrient, are recycled in the environment. plants absorb phosphorus compounds from the soil, and decaying organic matter, including both plant matter and animal droppings, returns it to the soil. phosphorus is a vital part of atp, the energy currency of all cells, and is vital to all forms of life.