Its has to be A that's just plain common sense
C) His work proving that unseen bacteria can cause disease.
Explanation:
Keratin are important for the structural integrity, cell function and the movement and the proliferation of the cell and healing of the wound. Different tissues in the body contains different combinations of the keratin proteins which play specialized roles.
Keratin has two major function in the skin -
- <u>To hold the cells present in the skin together and form a barrier</u>
- <u>It means the outermost layer of the skin which protects it from environment. </u>
- <u>It also prevents the tearing of the skin.</u>
It can be seen on a cladogram that modern birds and reptiles share a common ancestor. The piece of evidence that best supports this idea is <span>Feathers are a derived characteristic that first evolved in reptiles.
Both today's birds and ancient reptiles had feathers.</span>