The metazoa represent multi-cellular organisms. And we’re going to be focusing largely on the biology of metazoan cells this semester, and we’re going to be spending almost no time on plants. It’s not that plants aren’t important. It’s just that we don’t have time to cover everything. And, indeed, the molecular biology that you learn this semester will ultimately enable you to understand much about the physiology of multi-cellular plants which happen to be called metaphyta, a term you may never hear again in your entire life after today.