NEET BIOLOGY

Detailed explanation-1: -Solution: Squama means scale of skin. The scales of fish, reptiles and feathers of birds are grown from epithelium tissue.

Detailed explanation-2: -Feathers and scales are made up of two distinct forms of keratin, and it was long thought that each type of keratin was exclusive to each skin structure (feathers and scales). However, feather keratin is also present in the early stages of development of American alligator scales.

Detailed explanation-3: -A bird has scales over its legs and have many characters, including skull and skeleton, that are very reptilian. They are highly modified scales composed of beta keratin. A feather is a scale in which a long center shaft, the rachis, is the dominant feature.

Detailed explanation-4: -Scales of fishes and reptiles, feathers of birds, hairs, horns, hooves and nails of animals are all remnants of the exoskeleton. Q. Which of the following proteins is a constituent of nails, hair and feathers?

Detailed explanation-5: -New study suggests a common ancestor for all three skin coverings. Hair, scales, and feathers seem to have very little in common. But these structures appear to have evolved from a single ancestor-a reptile that lived 300 million years ago-according to new research.