(this is based upon an introductory level biology lab manual I once wrote) 

The Diversity of Life
 
 

Please take a few moments and think about all the different forms of life that you know about. You know about prokaryotes and eukarotes, about plants, fungi, protists, monerans and animals. Think about each one of those kingdoms, what you know about the defining differences between them and the breadth of lifeforms or body plans contained within them. Think of bacteria, protozoans, yeasts, mushrooms, of algae, lichens, mosses, ferns, begonias, corn and walnut trees, think of sponges, coral, giant clams, of squid, octopods, leeches and earthworms, think of scorpions, tarantulas, ticks, prawns, crabs and trilobites, think of earwigs, grasshoppers, mosquitoes and all the beetles you know of. Think of sea stars, sea squirts and acorn worms, of lancelets, lampreys, dogfish and salmon, of coelacanths, frogs and salamanders, of cobras and snapping turtles, of tyrannosaurids and turkeys, of platypuses, kangaroos, pygmy shrews and blue whales.

 This is the diversity of life