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These land snails have opercula, which helps identify them as "winkles gone ashore", in other words, snails within the clade Littorinimorpha and the informal group Architaenioglossa. Members of the snail family Pulmonata , which includes carboniferous land sails and some freshwater snails of the order Basommatophora , are protandrous ...
The freshwater snail Physa acuta is a self-fertile organism that can be exposed either to strong sexual selection or to self-fertilization depending on its mode of reproduction. Noel et al. [ 29 ] used Physa acuta to experimentally determine whether accumulation of deleterious mutations is avoided by inbreeding populations of the snail, as well ...
In 1995, there was a reported case of partial human parthenogenesis; a boy was found to have some of his cells (such as white blood cells) to be lacking in any genetic content from his father. Scientists believe that an unfertilized egg began to self-divide but then had some (but not all) of its cells fertilized by a sperm cell; this must have ...
Garden snails mating. A hermaphrodite (/ h ər ˈ m æ f r ə ˌ d aɪ t /) is a sexually reproducing organism that produces both male and female gametes. [1] Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.
Parthenogenesis is a mode of asexual reproduction in which offspring are produced by females without the genetic contribution of a male. Among all the sexual vertebrates, the only examples of true parthenogenesis, in which all-female populations reproduce without the involvement of males, are found in squamate reptiles (snakes and lizards). [1]
The anatomy of a common air-breathing land snail: much of this anatomy does not apply to gastropods in other clades or groups. Snails are distinguished by an anatomical process known as torsion, where the visceral mass of the animal rotates 180° to one side during development, such that the anus is situated more or less above the head. This ...
Japanese researchers announced last year that healthy fertile mice had been born using eggs created from male mice's tail-tip cells. The male-derived eggs were fertilized with regular sperm, thus ...
A slug on a wall in Kanagawa, Japan.. Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc.The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs (this is in contrast to the common name snail, which applies to ...