All multicellular organisms begin as zygotes. Shortly after forming, a zygote begins to divide. The single-celled zygote divides to form two new cells, then four, then elght, and so on. The division of each of these cells to form two new cells is called cleavage. Before each cleavage, or cell division, the genetic material in each cellis duplicated. This enables a cell to pass on a complete set of genes to the new cells formed by cell division. As you have read, the embryo develops In Its mother's uterus. It grows and becomes more complex until it is developed enough to leave the mother's body. The period from fertilization to birth, during which the offspring develops Inside the mother's body, is called pregnancy or the gestation perlod. In humans, the gestation period lasts about nine months. Pregnancy in humans is often discussed in terms of three three-month perlods called trimesters. Each trimester is characterized by specific changes in the developing offspring.

Are they describing "mitosis" or "melosis" In this paragraph? How can you tell?