D. fingernails
Skin, hair, and vertebrae are all the outer layer of the body and protect the body. The fingernails aren't part of that.
Answer:
NA+ gates open and flow into the Sarcolemma of the muscle fiber.
The answer is the last one
<span>The shape of a cell dictates the function of that cell. This is more pertinent to animal cells that, unlike plant cells, do not have a rigid cell wall. A misshapen cell cannot properly perform its intended function. </span>
Many ocean species (especially large ones like whales, sharks, and sea turtles) follow ocean currents to and from their feeding and breeding grounds.
