Which of the following is not considered a natural resource a. plastic b. gold c. titanium d. coal

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

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.

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm