If a boy notices a swelling around his nipples during puberty, what is the likely cause

What causes the force that pushes magma from the magma chamber through the pipe and vent of a volcano?

Consider this plant cell which organelle is labeled g

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.