A gamete is a haploid cell that fuses with another haploid cell during fertilization in organisms that sexually reproduce and possess only one set of dissimilar chromosomes. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller tadpole-like type—called a sperm. Sperm cells or spermatozoon are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell or a sperm. Ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information of an individual, one ploidy of each type, and are created through meiosis, in which a germ cell undergoes two fissions, resulting in the production of four gametes. In biology, the type of gamete one produces determines the classification of their sex.
In vitro studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from in vitro experiments may not fully or accurately predict the effects on a whole organism. In contrast to in vitro experiments, in vivo studies are those conducted in living organisms, including humans, and whole plants.
A mother is the female parent of a child. Mothers are women who inhabit or perform the role of bearing some relation to their children, who may or may not be their biological offspring. Thus, dependent on the context, women can be considered mothers by virtue of having given birth, by raising their child(ren), supplying their ovum for fertilisation, or some combination thereof. Such conditions provide a way of delineating the concept of motherhood, or the state of being a mother. Women who meet the third and first categories usually fall under the terms 'birth mother' or 'biological mother', regardless of whether the individual in question goes on to parent their child. Accordingly, a woman who meets only the second condition may be considered an adoptive mother, and those who meet only the first or only the third a surrogacy mother.
Oogenesis, ovogenesis, or oögenesis is the differentiation of the ovum into a cell competent to further develop when fertilized. It is developed from the primary oocyte by maturation. Oogenesis is initiated in the embryonic stage.
Insemination is the introduction of sperm into a female’s reproductive system for the purpose of impregnating or fertilizing the female for sexual reproduction. The sperm is introduced into the uterus of a mammal or the oviduct of an oviparous (egg-laying) animal. In mammals, insemination normally occurs during sexual intercourse or copulation, but insemination can take place in other ways, such as by artificial insemination.
Capacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte. This step is a biochemical event; the sperm move normally and look mature prior to capacitation. In vivo, capacitation occurs after ejaculation, when the spermatozoa leave the vagina and enter the superior female reproductive tract. The uterus aids in the steps of capacitation by secreting sterol-binding albumin, lipoproteins, and proteolytic and glycosidasic enzymes such as heparin.
Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse, which can lead to twin babies from two separate biological fathers. The term superfecundation is derived from fecund, meaning the ability to produce offspring. Homopaternal superfecundation refers to the fertilization of two separate ova from the same father, leading to fraternal twins; while heteropaternal superfecundation is referred to as a form of atypical twinning where, genetically, the twins are half siblings – sharing the same mother, but with different fathers.
Human fertilization is the union of a human egg and sperm, occurring in the ampulla of the fallopian tube. The result of this union, leads to the production of a zygote cell, or fertilized egg, initiating prenatal development. Scientists discovered the dynamics of human fertilization in the nineteenth century.
Human reproduction is any form of sexual reproduction resulting in human fertilization. It typically involves sexual intercourse between a man and a woman. During sexual intercourse, the interaction between the male and female reproductive systems results in fertilization of the woman's ovum by the man's sperm. These are specialized reproductive cells called gametes, created in a process called meiosis. While normal cells contains 46 chromosomes, 23 pairs, gamete cells only contain 23 chromosomes, and it is when these two cells merge into one zygote cell that genetic recombination occurs and the new zygote contains 23 chromosomes from each parent, giving them 23 pairs. A typical 9-month gestation period is followed by childbirth. The fertilization of the ovum may be achieved by artificial insemination methods, which do not involve sexual intercourse. Assisted reproductive technology also exists.
Childlessness is the state of not having children. Childlessness may have personal, social or political significance.
In vitro maturation (IVM) is the technique of letting the contents of ovarian follicles and the oocytes inside mature in vitro. It can be offered to women with infertility problems, combined with IVF, offering women pregnancy without ovarian stimulation.
Fallopian tube obstruction is a major cause of female infertility. Blocked fallopian tubes are unable to let the ovum and the sperm converge, thus making fertilization impossible. Fallopian tubes are also known as oviducts, uterine tubes, and salpinges.
Transvaginal oocyte retrieval (TVOR), also referred to as oocyte retrieval (OCR), is a technique used in in vitro fertilization (IVF) in order to remove oocytes from the ovary of a woman, enabling fertilization outside the body. Transvaginal oocyte retrieval is more properly referred to as transvaginal ovum retrieval when the oocytes have matured into ova, as is normally the case in IVF.
IVF or in vitro fertilization is an assisted reproductive technology that involves fertilisation of an egg outside of the human body.
Religious response to assisted reproductive technology (ART) deals with the new challenges for traditional social and religious communities raised by modern assisted reproductive technology (ART). Because many religious communities have strong opinions and religious legislation regarding marriage, sex and reproduction, modern fertility technology has forced religions to respond.
Howard Jones may refer to:
Astrue v. Capato, 566 U.S. 541 (2012), was a case in which the Supreme Court of the United States held that children conceived after a parent's death are not entitled to Social Security Survivors benefits if the laws in the state that the parent's will was signed in forbid it. The case was a unanimous decision.
LGBT parents in Canada have undergone significant progress in terms of both legal and social acceptance. Same-sex couples who wish for parenthood now enjoy equally the possibilities, responsibilities and rights of opposite-sex couples. Following the nationwide legalization of same-sex marriage in 2005, the number of LGBT families in Canada has increased substantially, paving the way for same-sex couples' aspirations of having their own children. Legal methods of assisted reproduction range from insemination via IVF through to surrogacy arrangements.
