the major difference between a cell that responds to a signal and one that does not is the presence of a

Look at the picture below . what does this picture represent ?

If the nucleus of a cell was removed the cell wouldn’t be able to make proteins because

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.