Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and bacteria. Many eukaryotic organisms including plants, animals, and fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited.
Reproduction is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual.
Sexual themes are frequently used in science fiction or related genres. Such elements may include depictions of realistic sexual interactions in a science fictional setting, a protagonist with an alternative sexuality, a sexual encounter between a human and a fictional extraterrestrial, or exploration of the varieties of sexual experience that deviate from the conventional.
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescopic development—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs.
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, survival value, and phylogeny of a behavior?
Maia is a fantasy novel by Richard Adams, published in 1984. It is set in the Beklan Empire, the fictional world of Adams's 1974 novel Shardik, to which it stands as a loose prequel, taking place a few years earlier.
Republic Commando: Hard Contact is the tie-in novel to the video game Republic Commando, written by Karen Traviss.
The Pirate Queen is a musical with music by Claude-Michel Schönberg, French lyrics by Alain Boublil and English lyric adaptations by Richard Maltby Jr. and John Dempsey. The French book was written by Boublil and Schönberg and the English book adaptation was by Maltby Jr.
Argiope bruennichi is a species of orb-web spider distributed throughout central Europe, northern Europe, north Africa, parts of Asia, and the Azores archipelago. Like many other members of the genus Argiope, it shows striking yellow and black markings on its abdomen.
Monogamous pairing in animals refers to the natural history of mating systems in which species pair bond to raise offspring. This is associated, usually implicitly, with sexual monogamy.
Mother of Demons is a science-fiction novel by American author Eric Flint. His debut novel, it was published in paperback form in 1997 by Baen Books. It was one of the first books published freely on the web by its author and publisher, as part of an experiment by Eric Flint and Jim Baen which led to more active electronic publishing by both. The story describes the aftermath of the crash of an interstellar starship on a world full of barely biologically compatible primitive but intelligent alien life.
Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization by sperm. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis.
While piracy was predominantly a male occupation, a minority of pirates were women. On many ships, women were prohibited by the ship's contract, which all crew members were required to sign.
A queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony. Some female ants, such as the Cataglyphis, do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning, and all of those offspring will be female. Others, like those in the genus Crematogaster, mate in a nuptial flight. Queen offspring ants develop from larvae specially fed in order to become sexually mature among most species. Depending on the species, there can be either a single mother queen, or potentially hundreds of fertile queens in some species. A queen of Lasius niger was held in captivity by German entomologist Hermann Appel for 283⁄4 years; also a Pogonomyrmex owyheei has a maximum estimated longevity of 30 years in the field.
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes (haploid) combines with another to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction does not occur in prokaryotes, but they have processes with similar effects such as bacterial conjugation, transformation and transduction, which may have been precursors to sexual reproduction in early eukaryotes.
Polygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.
Pemphigus betae, also known as the sugarbeet root aphid, is a species of gall-forming aphid that forms galls specifically on the commonly found narrowleaf cottonwood, Populus angustifolia. Sugarbeet root aphids have been found in North America and Europe. They infect sugarbeets, but also other plants like tablebeets and Swiss chard. Their size has been likened to that of a pinhead, and are pale white-yellow in color. Sugarbeet root aphids have soft bodies that are bulbous in shape, with mandibular parts that can pierce and suck and paired abdominal tubes that point backwards, and come in both winged and wingless forms. They are known for their consequential effects on agriculture due to infestation of plants, and efforts to control the pests have proved to be difficult.
Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts. Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations, with variations in depth of calls the speed of calls and other complex behaviours to attract mates. The fittest males will have the deepest croaks and the best territories, with females known to make their mate choices at least partly based on the males depth of croaking. This has led to sexual dimorphism, with females being larger than males in 90% of species, males in 10% and males fighting for groups of females.
Polyandry in fish is a mating system where females mate with multiple males within one mating season. This type of mating exists in a variety of animal species. Polyandry has been found in both oviparous and viviparous bony fish and sharks. General examples of polyandry occur in fish species, such as green swordtails and Trinidadian guppies. Specific types of polyandry have also been classified, such as classical polyandry in pipefish cooperative polyandry in cichlids and convenience polyandry in sharks.
Aphidius nigripes is a species of parasitoid wasp in the subfamily Aphidiinae of the family Braconidae. It is the most common parasitoid of the potato aphid Macrosiphum euphorbiae in eastern North America. Many other species of aphids may also serve as hosts.
