An embryo is a multicellulardiploid eukaryote in its earliest stage of development, from the time of first cell division untilbirth, hatching, or germination. In humans, it is called an embryo until about eight weeks afterfertilization (i.e. ten weeks LMP), and from then it is instead called a fetus.
The development of the embryo is called embryogenesis. In organisms that reproduce sexually, once a sperm fertilizes an egg cell, the result is a cell called the zygote that has half of the DNA of each of two parents. The resulting embryo derives 50 percent of its genetic makeup from each parent. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism. The result of this process is an embryo.
15 мар 2010
