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Maternal to zygotic transition (MZT), also known as embryonic genome activation, is the stage in embryonic development during which development comes under the exclusive control of the zygotic genome rather than the maternal (egg) genome. The egg contains stored maternal genetic material mRNA which controls embryo development until the onset of ...
The zygote is the earliest developmental stage. In humans and most other anisogamous organisms, a zygote is formed when an egg cell and sperm cell come together to create a new unique organism. The formation of a totipotent zygote with the potential to produce a whole organism depends on epigenetic reprogramming.
The embryo is joined to the trophoblastic shell by a narrow connecting stalk that develops into the umbilical cord to attach the placenta to the embryo. [ 11 ] [ 15 ] Arteries in the decidua are remodelled to increase the maternal blood flow into the intervillous spaces of the placenta, allowing gas exchange and the transfer of nutrients to the ...
Fertilization was not understood in antiquity. Hippocrates believed that the embryo was the product of male semen and a female factor. Aristotle held that only male semen gave rise to an embryo, while the female only provided a place for the embryo to develop, [5] a concept he acquired from the preformationist Pythagoras.
Development before birth, or prenatal development (from Latin natalis 'relating to birth') is the process in which a zygote, and later an embryo, and then a fetus develops during gestation. Prenatal development starts with fertilization and the formation of the zygote , the first stage in embryonic development which continues in fetal ...
The nervous system develops enough to control some body functions. The eyelids open and close. The cochleae are now developed, though the myelin sheaths in neural portion of the auditory system will continue to develop until 18 months after birth. The respiratory system, while immature, has developed to the point where gas exchange is possible.
The embryo becomes embedded in the endometrium in a process called implantation. In most successful pregnancies, the embryo implants 8 to 10 days after ovulation. [7] The embryo, the extra-embryonic membranes, and the placenta are collectively referred to as a conceptus, or the "products of conception".
Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control. The introduction of the birth control pill ("the Pill") in 1960 revolutionized the options for contraception, sparking vibrant discussion in the scientific and social science literature and in the media.