You are outside playing on a hot sunny day and are called into your home by your parents. a stone fence surrounds your yard. as you enter the gate, you touch the stones in the fence and notice how warm it is. you let your hand stay on the rocks of the wall for a few minutes. when you remove your hand and touch your face with it, you can feel the heat; the stones in the wall have warmed your hand. a) radiation b) conduction c) convection

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.