What causes the stoma to open? A. When the guard cells are full of water, they become stiff and hold
the pore open.
B. When the guard cells get covered in wax, they become limp and
the pore opens
C. When the guard cells are empty, they become limp and the pore
opens.
D. When the guard cells inflate with oxygen, they become stiff and
the pore opens.

Which is an example of a population?

Name the part of the the brain labeled "e".

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.