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Gamete intrafallopian transfer (GIFT) is a tool of assisted reproductive technology against infertility. Eggs are removed from a woman's ovaries, and placed in one of the fallopian tubes , along with the man's sperm.
In zygote intrafallopian transfer (ZIFT), egg cells are removed from the woman's ovaries and fertilized in the laboratory; the resulting zygote is then placed into the fallopian tube. Cytoplasmic transfer is the technique in which the contents of a fertile egg from a donor are injected into the infertile egg of the patient along with the sperm.
Cryptic female choice is a form of mate choice which occurs both in pre- and post-copulatory circumstances in which females of certain species use physical or chemical mechanisms to control a male's success of fertilizing their ova or ovum; i.e. by selecting whether sperm are successful in fertilizing their eggs or not.
In contrast, in natural fertilization sperm compete and when the first sperm penetrates the oolemma, the oolemma hardens to block the entry of any other sperm. Concern has been raised that in ICSI this sperm selection process is bypassed and the sperm is selected by the embryologist without any specific testing.
In vitro fertilization experiments in the mouse, provided evidence of sperm selection at the gametic level. [56] When sperm of sibling and non-sibling males were mixed, a fertilization bias towards the sperm of the non-sibling males was observed. The results were interpreted as egg-driven sperm selection against related sperm.
Fertilization occurs when the sperm successfully enters the ovum's membrane. The chromosomes of the sperm are passed into the egg to form a unique genome. The egg becomes a zygote and the germinal stage of embryonic development begins. The germinal stage refers to the time from fertilization, through the development of the early embryo, up ...
Human embryology is the study of this development during the first eight weeks after fertilization. The normal period of gestation (pregnancy) is about nine months or 36 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus.
Embryo transfer refers to a step in the process of assisted reproduction in which embryos are placed into the uterus of a female with the intent to establish a pregnancy.This technique - which is often used in connection with in vitro fertilization (IVF) - may be used in humans or in other animals, in which situations and goals may vary.