Answer:
Moving things in and out of the cell is an important role of the plasma membrane. It controls everything that enters and leaves the cell. There are two basic ways that substances can cross the plasma membrane: passive transport, which requires no energy; and active transport, which requires energy.
Please rephrase the question, it doesn't make sense.
Water is important because, it's a part of all bodily functions
Your question doesn't make sense. Mitisis IS the process by which humans grow, thus increasing the number of cells in the body. Mitosis is a process that includes 4 phases. What exactly are you asking?