ToeToes are the digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being digitigrade. Humans, and other animals that walk on the soles of their feet, are described as being plantigrade; unguligrade animals are those that walk on hooves at the tips of their toes. StructureThere are normally five toes present on each human foot.
ClawA claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles, spiders, and velvet worms have somewhat similar fine, hooked structures at the end of the leg or tarsus for gripping a surface as they walk. The pincers of crabs, lobsters, crayfish, shrimps, prawns and scorpions, more formally known as their chelae, are sometimes called claws.
ProteinBiomolecule consisting of chains of amino acid residuesA representation of the 3D structure of the protein myoglobin showing turquoise α-helices. This protein was the first to have its structure solved by X-ray crystallography. Toward the right-center among the coils, a prosthetic group called a heme group (shown in gray) with a bound oxygen molecule (red).Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acidresidues.
PrimatePrimates is an order of mammals, which is further divided into the strepsirrhines, which include lemurs, galagos, and lorisids; and the haplorhines, which include tarsiers and simians (monkeys and apes).
Alpha-keratinAlpha-keratin, or α-keratin, is a type of keratin found in mammalian vertebrates. This protein is the primary component in hairs, horns, claws, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure. The secondary structure of α-keratin is very similar to that of a traditional protein α-helix and forms a coiled coil.
FingerA finger is a prominent, multi-jointed digit on the forelimbs of tetrapod vertebrate animals with prehensile extremities (i.e. hands) such as humans and other primates, and is typically covered with a keratinized nail to protect the end (i.e. fingertip). Most tetrapods have five digits (pentadactyly), digits that are significantly shorter than the metacarpal/metatarsals, are typically referred to as toes; while digits that are notably elongated are called fingers.
MarmosetThe marmosets (), also known as zaris or sagoin, are twenty-two New World monkey species of the generaCallithrix, Cebuella, Callibella, and Mico. All four genera are part of the biological familyCallitrichidae. The term "marmoset" is also used in reference to Goeldi's marmoset, Callimico goeldii, which is closely related.
PolymerIUPAC definitionA polymer is a substance composed of macromolecules. A macromolecule is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass.
Horn (anatomy)A horn is a permanent pointed projection on the head of various animals that consists of a covering of keratin and other proteins surrounding a core of live bone. Horns are distinct from antlers, which are not permanent. In mammals, true horns are found mainly among the ruminantartiodactyls, in the families Antilocapridae (pronghorn) and Bovidae (cattle, goats, antelope etc.).
Digit (anatomy)A digit is one of several most distal parts of a limb, such as fingers or toes, present in many vertebrates. NamesSome languages have different names for hand and foot digits (English: respectively "finger" and "toe", German: "Finger" and "Zeh", French: "doigt" and "orteil").
TetrapodA tetrapod (; from Ancient Greek τετρα (tetra) 'four' and πούς (poús) 'foot') is any vertebrate animal of the clade Tetrapoda (). The main diagnostic and defining trait (synapomorphy) of tetrapods is having four limbs, connected to the shoulder- and pelvic girdles, for which the group is named.
HoofThe hoof (pl.: hooves or hoofs) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering. Hooves are present in some even-toed and odd-toed placental mammals, as well as in some nonmammalians.*As an Amazon Associate I earn from qualifying purchases.