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Cockatiel Colour Genetics
The science of cockatiel colour genetics deals with the heredity of colour variation in the feathers of cockatiels, ''Nymphicus hollandicus''. Colour mutations are a natural but very rare phenomenon that occur in either captivity or the wild. About fifteen primary colour mutations have been established in the species which enable the production of many different combinations. Note that this article is heavily based on the captive or companion cockatiel rather than the wild cockatiel species. Mutations (list) * Anti-Dimorphic (ADM) Pied/Recessive Pied * Ashenfallow, incorrectly known as either Recessive Silver and/or Silver Fallow in the past * Bronzefallow/Brownfallow * Cinnamon * Dilute, incorrectly known as Pastel Silver in the past * Dominant Silver/Ashen Dilute * Edgedilute, incorrectly known as Spangled Silver in the past * Faded * Sex-linked Ino/ Lutino/Albino *Palefaced Ino/Creamino * Non-sex-linked ino/Recessive Ino * Opaline/Pearl * Palefaced, often incorrectly known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eumelanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. The melanin pigments are produced in a specialized group of cells known as melanocytes. Functionally, eumelanin serves as protection against UV radiation. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. The most common type is eumelanin, of which there are two types— brown eumelanin and black eumelanin. Pheomelanin, which is produced when melanocytes are malfunctioning due to derivation of the gene to its recessive format is a cysteine-derivative that contains poly benzothiazine portions that are largely responsible for the of red yellow tint given to some skin or hair colors. Neuromelanin is found in the brain. Research has been u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. The melanin pigments are produced in a specialized group of cells known as melanocytes. Functionally, eumelanin serves as protection against Ultraviolet, UV radiation. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. The most common type is eumelanin, of which there are two types— brown eumelanin and black eumelanin. Pheomelanin, which is produced when melanocytes are malfunctioning due to derivation of the gene to its recessive format is a cysteine-derivative that contains polybenzothiazine portions that are largely responsible for the of red yellow tint given to some skin or hair colors. Neuromelanin is found in the brain. Research ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Linkage
Sex linked describes the sex-specific patterns of inheritance and presentation when a gene mutation (allele) is present on a sex chromosome (allosome) rather than a non-sex chromosome (autosome). In humans, these are termed X-linked recessive, X-linked dominant and Y-linked. The inheritance and presentation of all three differ depending on the sex of both the parent and the child. This makes them characteristically different from autosomal dominance and recessiveness. There are many more X-linked conditions than Y-linked conditions, since humans have several times as many genes on the X chromosome than the Y chromosome. Only females are able to be carriers for X-linked conditions; males will always be affected by any X-linked condition, since they have no second X chromosome with a healthy copy of the gene. As such, X-linked recessive conditions affect males much more commonly than females. In X-linked recessive inheritance, a son born to a carrier mother and an unaffected fath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Budgerigar
The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet or shell parakeet, is a small, long-tailed, seed-eating parrot usually nicknamed the budgie ( ), or in American English, the parakeet. Budgies are the only species in the genus ''Melopsittacus''. Naturally, the species is green and yellow with black, scalloped markings on the nape, back, and wings. Budgies are bred in captivity with colouring of blues, whites, yellows, greys, and even with small crests. Juveniles and chicks are monomorphic, while adults are told apart by their cere colouring, and their behaviour. The species is the only member of the genus ''Melopsittacus'', which is the only genus in the Melopsittacini tribe. The origin of the budgerigar's name is unclear. First recorded in 1805, budgerigars are popular pets around the world due to their small size, low cost, and ability to mimic human speech. They are likely the third most popular pet in the world, after the domesticated d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rosella
Rosellas are in a genus that consists of six species and nineteen subspecies. These colourful parrots from Australia are in the genus ''Platycercus''. ''Platycercus'' means "broad-tailed" or "flat-tailed", reflecting a feature common to the rosellas and other members of the broad-tailed parrot tribe. Their diet is mainly seeds and fruit. Taxonomy The genus was described by naturalist Nicholas Aylward Vigors in 1825; the name ''Platycercus'' derived from the Greek ''platykerkos'' meaning "broad-" or "flat-tailed", from ''platys'' "broad, wide, level, flat" and ''kerkos'' "tail of a beast"., , . The relationships with other parrots have been unclear, with the Australian ringneck (genus '' Barnardius'') cited as a closest relative by some, and the genus '' Psephotus'' by others; the plumage of the western rosella seen as a link to the latter genus. Early European settlers encountered the eastern rosella at Rose Hill, New South Wales, now Parramatta, and so they called it the R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macaw
Macaws are a group of New World parrots that are long-tailed and often colorful. They are popular in aviculture or as companion parrots, although there are conservation concerns about several species in the wild. Biology Of the many different Psittacidae (true parrots) genera, six are classified as macaws: ''Ara'', ''Anodorhynchus'', '' Cyanopsitta'', ''Primolius'', ''Orthopsittaca'', and ''Diopsittaca''. Previously, the members of the genus ''Primolius'' were placed in ''Propyrrhura'', but the former is correct in accordance with ICZN rules. In addition, the related macaw-like thick-billed parrot is sometimes referred to as a "macaw", although it is not phylogenetically considered to be a macaw species. Macaws are native to Central America and North America (only Mexico), South America, and formerly the Caribbean. Most species are associated with forests, but others prefer woodland or savannah-like habitats.Abramson, J., Speer, B. L., & Thomsen, J.B. 1999, "The Large Macaws, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lovebird
Lovebird is the common name for the genus ''Agapornis'', a small group of parrots in the Old World parrot family Psittaculidae. Of the nine species in the genus, all are native to the African continent, with the grey-headed lovebird being native to the African island of Madagascar. Social and affectionate, the name comes from the parrots' strong, monogamous pair bonding and the long periods which paired birds spend sitting together. Lovebirds live in small flocks and eat fruit, vegetables, grasses, and seeds. Black-winged lovebirds also eat insects and figs, and black-collared lovebirds have a special dietary requirement for native figs, making them difficult to keep in captivity. Some species are kept as pets, and several coloured mutations have been selectively bred in aviculture. The average lifespan is 20 to 30 years. Description Lovebirds are in length, up to 24 cm in wingspan with 9 cm for a single wing and in weight. They are among the smallest parrots, char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conure
Conures are a diverse, loosely defined group of small to medium-sized parrots. They belong to several genera within a long-tailed group of the New World parrot subfamily Arinae. The term "conure" is used primarily in bird keeping, though it has appeared in some scientific journals. The American Ornithologists' Union uses the generic term ''parakeet'' for all species elsewhere called ''conure'', though Joseph Forshaw, a prominent Australian ornithologist, uses ''conure''. Description Conures are either large parakeets or small parrots found in the Western Hemisphere. They are analogous in size and way of life to Afro-Eurasia's rose-ringed parakeets or the Australian parakeets. All living conure species live in Central and South America. The extinct ''Conuropsis carolinensis'', or Carolina parakeet was an exception. Conures are often called the clowns of the parrot world due to their constant attention seeking behavior including hanging upside-down and swaying back and fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
