Abortion An abortion is the termination of a pregnancy by the removal or expulsion from the uterus of a fetus/embryo, resulting in or caused by its death. An abortion can occur spontaneously due to complications during pregnancy or can be induced, in humans and other species. Abortion
Bird Birds (class Aves) are winged, bipedal, endothermic (warm-blooded), vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Bird
Tree Sparrow The Tree Sparrow, Passer montanus, is a passerine bird in the family Passeridae with a rich chestnut crown and nape, and a black patch on each pure white cheek. The sexes are similarly plumaged, and young birds are a duller version of the adult. This sparrow breeds over most of temperate Eurasia and Southeast Asia, and has been introduced elsewhere, including the United States (where it is known as the Eurasian Tree Sparrow or German Sparrow to differentiate it from the native, unrelated American Tree Sparrow). Tree_Sparrow
Plains Zebra The Plains zebra (Equus quagga, formerly Equus burchelli), also known as the Common zebra or the Burchell's zebra, is the most common and geographically widespread form of zebra. It once ranged from the south of Ethiopia right through east Africa as far south as Angola and eastern South Africa. Plains_Zebra
B chromosome karyotype, wild populations of many animal and plant species contain B chromosomes (also known as supernumerary or accessory chromosomes). By definition, these chromosomes are not essential for the life of a species, and are lacking in some (usually most) of the individuals. B_chromosome
Snowfinch In Europe, "Snowfinch" is often used for the White-winged Snowfinch specifically. "Pyrgilauda" redirects here. In the late 20th century, this was occasionally believed to be a junior synonym of Eremopterix (see also below).The snowfinches make up the passerine bird genus Montifringilla. Despite their common name, they are Old World sparrows (family Passeridae), not true finches (family Fringillidae). The genus is sometimes split into three. Snowfinch
Species group species group is an informal taxonomic rank into which an assemblage of closely-related species within a genus are grouped because of their morphological similarities and their identity as a biological unit with a single monophyletic origin. Species_group