This is a closed word sort that I use to start my biology unit in Science at the Intermediate level. For older students print it in black and white, and for slower or younger students, print it in color. The categories are color and text clued to give the kids a hand, and this kind of word sort is very helpful in introducing students to words they may not be familiar with.
My only introduction is that the students are to sort the words into categories--then I let the students sort them. The category headings are included, but you can take them out if you want to do an open word sort. You can assess prior knowledge and also have students discover for themselves how scientists classify living things. I usually have students glue the words onto construction paper and draw lines to show relationships. Sometimes they illustrate the words that they know.