Tissues are an important topic of conversation when it comes to biology. They usual sit at the front end of a biology course. When we look at tissues, what we need to think about are the cells of the body. Around about 30 trillion and around about 200 types of e so what does that mean? Ah, this is a long time coming. We could have done this, or should have probably done this, about three years ago. Or they don't even need to be a student to listen. I tis their course.