Answer:
neither
Explanation:
because humans are the ones that make energy available for cell activity
<span>Sunlight CO2 and Water
</span>
<span>Epithelial tissue is densely packed cells that used most in the area where protection is needed. This cells mostly used in skin, some with more keratin which will increase their ability to protect. In bone, the main protective layer is calcium mineral which was deposited by osteocytes. Because this bone doesn't really need more epithelial cells. Bone tissue only needs a good vascularization and connective tissue to support it.
</span>
Answer:
The correct answer is option 3. "secondary structure".
Explanation:
The secondary structure of polypeptide and proteins refers to the second order of folding, including common structures such as beta sheets, alpha helix, as well as turns and loops. The hydrogen bonds between the oxygen and nitrogen atoms of the peptide bonds are crucial to secondary structures, as these hydrogen bonds form and stabilize the aforementioned common structures.
