Joseph fell out a tree while he was hunting and broke his back. After being paralyzed for three years, he obtained an experimental medical procedure that implanted into his spinal cord. These cells regenerated in his spinal cord and allowed him to begin to walk again.

a.) a destruction fo cells by viral reproduction

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.