In order to detect a signal (that is, to be a target cell), a neighbor cell must have the right receptor for that signal. When a signaling molecule binds to its receptor, it alters the shape or activity of the receptor, triggering a change inside of the cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
A chunk paragraph is just a way of developing your skill in writing - it is a style or format which forces you to explain your ideas and arguments. Here's you do chunk writing: Write your topic sentence.
Chunky Lyrics Bruno Mars. She got to shake her little something (shake her little something), ooh. Throwing that thing from left, right, side to side. She got to have her own money (she got her own money), oh yeah. Shout out to the girls that pay they rent on time. If you ain't here to party take your ass back home.