Regulation, Mitosis, an Meiosis.

Regulation is the life process by which organisms and cells respond to our constantly changing internal and external environment. This is important because an upset in homeostasis in any one of an organism's systems might result in an imbalance in the organism's homeostasis. In humans, regulation consists of the endocrine and nervous systems. The endocrine system is made up of many organs that produce hormones into the bloodstream. The nervous system carries messages in the …

…in animals or spores in plants with half the number of chromosomes as the parent cell. Meiosis is a sexual process opposed to mitosis which is an asexual process. While in mitosis the cell divides once, in meiosis the cell divides twice, yielding four daughter cells. Cells produced by mitosis are diploid, and cells produces by meiosis are monoploid. Crossing-over may occur in meiosis, but not mitosis. In both processes, the chromosomes replicate only once.