If you are referring to the different stages of growth and development within the womb, these as the Z.E.F: Zygote, Embryo and Fetus. The initial development begins with the fertilization of the egg, where the male gamete, which is a sperm cell, fuses with the female gamete, her egg. This creates a zygote which is implanted in the woman's uterus. By this stage, the woman is technically pregnant. The next stage includes the zygote being embedding into the lining of the uterus, which is also called the endometrium, which forms the placenta. The placenta brings nutrition to the zygote and is essentially what it feeds from, through nutrients being sent through the wall of the uterus.
An umbilical cord also assists with this stage by ensuring as little waste from the zygote is left after it receives the nutrients that are sent into the uterus. Prior to the placenta, nutrients can only be received through a blastocyst, which comes from something called the yolk sac. Rapid changes occur in the zygote stage, including extreme cell divisions. However, there is a lack of significant growth itself, in this stage. This occurrence is called the cleavage, meaning that despite such rapid and noticeable changes within the zygote, there is very little by way of size growth.
Following this, the zygote then becomes an embryo, after cellular differentiation. The embryo then grows to the stage of a fetus, following which, the mother gives birth and the fetus becomes a baby, or a child. Any following growth steps following this become ages, in most cultures. Further stages of growth and development after birth generally refer to how the baby develops physically, emotionally and socially. It looks into speech and how the child interacts with its environment as it gets older. For example, a child should be able to talk fluently by the age of five.
An umbilical cord also assists with this stage by ensuring as little waste from the zygote is left after it receives the nutrients that are sent into the uterus. Prior to the placenta, nutrients can only be received through a blastocyst, which comes from something called the yolk sac. Rapid changes occur in the zygote stage, including extreme cell divisions. However, there is a lack of significant growth itself, in this stage. This occurrence is called the cleavage, meaning that despite such rapid and noticeable changes within the zygote, there is very little by way of size growth.
Following this, the zygote then becomes an embryo, after cellular differentiation. The embryo then grows to the stage of a fetus, following which, the mother gives birth and the fetus becomes a baby, or a child. Any following growth steps following this become ages, in most cultures. Further stages of growth and development after birth generally refer to how the baby develops physically, emotionally and socially. It looks into speech and how the child interacts with its environment as it gets older. For example, a child should be able to talk fluently by the age of five.
