<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>
Are you asking what their predators are? As adults, the Australian meat ants can eat them. As tadpoles, they are eaten by camen, catfish, cat-eyed snakes.
With fossils, scientists can use carbon dating to determine the approximate age of whatever fossil they have.
In DIFFUSION AND FACILITATED DIFFUSION no energy is used. The one that needs a helper to get thing across is FACILITATED DIFFUSION.<span> Facilitated diffusion involves the diffusion of materials across the cell plasma membrane with the aid of membrane proteins such as carriers and channels. The process of diffusion does not need a carrier, the molecules to be transported just move on their own from the area of high concentration to the region of low concentration until the concentration in the space become uniform.</span>
