Man - this is a dualistic creature. I.e.If we consider it from a purely physiological and biological side, to accomplish the most important tasks or instinct - procreation, it requires two kinds of sex cells - the male sex klekti (sperm), which carry the genetic material, and (egg), in that this material originates in the future embryo. Kohso during childbirth, the light appears the long-awaited baby sizes of about 50-54 cm, no one even thought does not come from a small cell he actually developed. The size of the female reproductive cells varies between 0.2-0.3 mm, and in spite of such a small razmerchik (at human scale), the egg is the largest bical cell in the women's (and indeed human) body. If you remember school biology course, any cell consists of two main parts - the nucleus and the body (shell). In geometric terms, the body of the egg and its shell is spherical in shape. The shell has a porous structure, which accumulates in the cells of nutrient for embryofor, to put it simply - the yolk. Inside the shell with a certain eccentricity in relation to the center, the core is located, which in turn is composed of a large nucleus and chromatin inner shell. It should also be noted that the development of eggs in a woman's body takes a little differently than in the male:
sperm exprIt is activated continuously throughout the reproductive life of a man, but the egg - periodically (menstrual cycle).