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Poa alpina, a grass which shows vivipary: the seeds germinate while still attached to the mother plant.
A viviparous animal is an animal employing vivipary: the embryo develops inside the body of the mother, as opposed to outside in an egg (ovipary). The mother then gives live birth. The less developed form of vivipary is called ovoviviparity, which, for instance, occurs in most vipers. The more developed form of vivipary is called placental viviparity; mammals are the best example, but it has also evolved independently in other animals, such as in scorpions, some sharks, and in velvet worms. Viviparous offspring live independently and require an external food supply from birth. Certain lizards also employ this method such as the genera Tiliqua and Corucia. The placenta is attached directly to the mother in these lizards which is called viviparous matrotrophy. There are numerous advantages and disadvantages to being viviparous.
| Human physiology and endocrinology of reproduction | |
|---|---|
| Anatomy and physiology | Reproductive system (male, female) |
| Menstrual/Estrous cycle | Menstruation - Follicular phase - Ovulation - Luteal phase |
| Gametogenesis | Spermatogenesis (spermatogonium, spermatocyte, spermatid, sperm) - Oogenesis (oogonium, oocyte, ootid, ovum) - Germ cell (gonocyte, gamete) |
| Sexuality | Human sexual behavior - Sexual intercourse - Erection - Ejaculation - Orgasm - Insemination - Fertilisation/Fertility - Masturbation - Pregnancy - Postpartum period |
| Lifespan | Prenatal development - Sexual dimorphism - Sexual differentiation - Puberty (Menarche, Adrenarche) - Maternal age/Paternal age - Climacteric (Menopause, Andropause) |
| Eggs | Ovum - Oviposition - Oviparity - Ovoviviparity - Viviparity |
| Reproductive endocrinology | Hypothalamic-pituitary-gonadal axis - Andrology - Hormone |
 | This developmental biology article is a stub. You can help Wikipedia by expanding it. |
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