We have bacteria and we also have archae. So basically, archae are single celled organisms that include those organisms that are capable of living in very harsh and hostile environments, such as very high temperatures, very high or very low PH, very high acidity, very salty, and so forth. So those organisms that can live in very hostile environments usually fall into domain known as rkey. And these are the organisms we call prokaryotes. So we have bacteria and we have these. Now, what exactly are the different types of shapes of our prokaryotic organism?