How do adult stem cells differ from embryonic stem cells? a. adult stem cells have high healing potential, and embryonic stem cells have low healing potential. b. adult stem cells can only be used by adults, and embryonic stem cells can only be used by babies. c. adult stem cells have unipotency, and embryonic stem cells have pluripotency. d. adult stem cells have totipotency, and embryonic stem cells have multipotency.

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.