Answer:
keratin.
Explanation:
keratin is a fibrous protein that has protective and structural functions in the body.
to fulfil it's functional necessities keratin has characteristics that makes it insoluble and repellent to damage.
to fulfil it's functional necessities keratin has characteristics that makes it insoluble and repellent to damage.in the human body, keratin can be present in - hair and finger nails.
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