Iris pigment epitheliumThe iris pigment epithelium (IPE) is a one cell thick layer of cuboidal cells lying behind the iris. The epithelial cells are highly pigmented due to the numerous large melanosomes which pack the cytoplasm of each cell. Towards the central axis, the IPE terminates at the pupillary margin. Peripherally, the IPE is continuous with the inner, non-pigmented layer of the ciliary epithelium.
MelaninGroup of natural pigments found in most organismsMicrograph of melanin pigment (light refracting granular material—center of image) in a pigmented melanomaMicrograph of the epidermis, with melanin labeled at leftMelanin ( ; from Ancient Greek μέλας (mélas) 'black, dark') is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms.
AlbinismAlbinism is the congenital absence of pigmentation (in mammals, melanin) in an animal or plant resulting in "hair being white, red, or yellow", "feathers, scales, and skin being yellow", "eyes being red, pink, purple, violet, or blue", and "leaves or stems being white or yellow", if applicable. Individuals with the condition are referred to as albinos. Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify.
TyrosinaseMore reference expression dataBioGPSEnsemblUniProtRefSeq (mRNA)RefSeq (protein)Location (UCSC)Chr 11: 89.18 – 89.3 MbChr 7: 87.07 – 87.14 MbPubMed searchWikidataTyrosinase is an oxidase that is the rate-limitingenzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway.
Biological pigmentA biological pigment, also known simply as a pigment or biochrome, is a substance produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan.
MammalA mammal (from Latin'breast') is a vertebrate animal of the classMammalia (). Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous period over 300 million years ago.
AmphibianAmphibians are ectothermic, anamniotic, four-limbedvertebrateanimals that constitute the classAmphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods, but excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant (living) amphibians belong to the monophyleticsubclassLissamphibia, with three living orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians).
ReptileClass of animalsReptiles, as commonly defined, are tetrapodvertebrateanimals with an ectothermic metabolism and amniotic development. Reptiles traditionally comprise four orders: Testudines (turtles), Crocodilia (crocodiles, alligators and gharials), Squamata (lizards and snakes) and Rhynchocephalia (tuatara), with about 12,000 extant species listed in the Reptile Database.
MelanismMelanism is a congenital high level of melanin in an organism resulting in dark pigmentation. Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the body of an animal, making it appear melanistic. Melanosis is hyperpigmentation associated with increased melanin, which occurs as part of a number of conditions, some are benign (like freckles). Others are (or can become) malignant.
FishA fish is an aquatic, anamniotic, gill-bearing vertebrateanimal with a tough cranium to protect the brain, but lacking limbs with digits. Fish can be grouped into the more basaljawless fish and the more common jawed fish, the latter including all livingcartilaginous and bony fish, as well as the extinct placoderms and acanthodians.
BirdWarm-blooded animals with wings and feathersBirds are a group of warm-bloodedvertebrateanimals constituting the classAves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. They live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich.
GeneticsScience of genes, heredity and variationGenetics is the study of genes, genetic variation, and in organisms. It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a MoravianAugustinian 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.*As an Amazon Associate I earn from qualifying purchases.