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.
Detail.) Because they don't do dinner (Body-Paragraph: Topic. Detail. Detail. Detail.) Chuck tomatoes, serve cake (Conclusion-Paragraph: Thesis. Summary. Connection.) [b]Backwards Construction:[/b] 5 paragraph essays are written [b]backwards.[/b] Step 1: Pick your [http://lessons.engrade.com/essaytopic Essay Topic]. Step 2: Create a [http://lessons.engrade.com/essaythesis Thesis].