Question

Horns of most mammals are composed of
A) Bones
B) Cartilage
C) Keratin
D) Chitin

Answer 1

Horns are branchless, two-part structures with a bony core and lined by a scleroprotein sheath (the same material found in human hair and nails), that grows from specialised hair follicles. Horns are a permanent feature and, in several species, grow ceaselessly.

Complete answer:
Keratin within the cuticle once cornified and thickened is known as horn. Horn of mammals is proof against mechanical and chemical injury because of this scleroprotein; the term ‘keratin’ stood for all of the proteins extracted from skin modifications, like horns, claws and hooves.
Afterwards, it had been completed that this scleroprotein is actually a mixture of keratins, scleroprotein filament-associated proteins and different proteins, like enzymes.
Keratins were then outlined as sure filament-forming proteins with specific chemistry properties and extracted from the cornified layer of the cuticle, whereas those filament-forming proteins that were extracted from the living layers of the cuticle were classified as ‘prekeratins’ or ‘cytokeratins’. Currently, the term ‘keratin’ covers all intermediate filament-forming proteins with specific chemistry properties and created in any vertebrate epithelia.
Keratin may be a vital macromolecule for healthy hair, skin, and nails. It's conjointly a really important part of the lining of the inner organs. sure foods contain nutrients that support the formation of scleroprotein within the body.

Hence: the option C is the correct answer.

Note:
Scleroprotein may be a vital macromolecule within the cuticle. scleroprotein has 2 main functions: to stay cells to each different and to form a protecting layer on the surface of the skin. In tissue cells, scleroprotein proteins within the cell attach to proteins mentioned as desmosomes on the surface.