Search results
Results from the WOW.Com Content Network
Veterinary obstetrics are the obstetrical methods used in veterinary medicine, which are quite different from those of human medicine. Veterinary obstetrics is a branch of veterinary medicine that deals with medical and surgical care together with manipulations of the female animals in breeding , gestation , labor , puerperium (postpartum ...
Parthenogenesis does not apply to isogamous species. [44] Parthenogenesis occurs naturally in aphids, Daphnia, rotifers, nematodes, and some other invertebrates, as well as in many plants. Among vertebrates, strict parthenogenesis is only known to occur in lizards, snakes, [45] birds, [46] and sharks. [47]
It has broad shiny oval leaves 10–35 cm (4–14 in) long and 5–15 cm (2–6 in) broad; leaf size is largest on young plants (occasionally to 45 cm or 17 + 1 ⁄ 2 in long), much smaller on old trees (typically 10 cm or 4 in long). The leaves develop inside a sheath at the apical meristem, which grows larger as the new leaf develops. When it ...
The more developed form of viviparity 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. [16] [17] [18] Viviparous offspring live independently and require an external food supply from birth.
The embryological origin of the mouth and anus is an important characteristic, and forms the morphological basis for separating bilaterian animals into two natural groupings: the protostomes and deuterostomes. In animals at least as complex as an earthworm, a dent forms in one side of the early, spheroidal embryo.
In these large animals, the birth process is similar to that of a human, though in most the offspring is precocial. This means that it is born in a more advanced state than a human baby and is able to stand, walk and run (or swim in the case of an aquatic mammal) shortly after birth.
The APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank. The monocotyledons include about 70,000 species, about a quarter of all angiosperms. The largest family in this group (and in the flowering plants as a whole) by number of species are the orchids (family Orchidaceae ), with more than ...
In placental mammals, the umbilical cord (also called the navel string, [1] birth cord or funiculus umbilicalis) is a conduit between the developing embryo or fetus and the placenta. During prenatal development , the umbilical cord is physiologically and genetically part of the fetus and (in humans) normally contains two arteries (the umbilical ...