D. It's harder body parts. A lot of fossils are of the skull, therefore that would lead one to think that it would be harder<span />
Produce energy usable by the cells of their respective organisms.
A characteristic of protein synthesis prokaryotes... Letter A
1. electrical signals travel toward the heart. 2. signal received by the atrioventricular node. 3.signal by the nodes in the atrium. 4.the atria contracts. 5. signal transferred to the ventricles. 6. the ventricles contract.
Cells lining the small intestine are specialized for absorption of nutrients. their plasma membrane <span>has </span><span>microvillus </span>(plural:<span> m</span>icrovilli)<span> which</span><span> increase cell surface area. These are cellular membranes that are microscopic in nature that increases the surface area of the cell for diffusion and minimize increase in volume.</span><span> </span>