Animals can be divided into groups ... Reptiles can live in many different places, like deserts, forests, and oceans. Some examples of reptiles are snakes, lizards, crocodiles, and turtles!

Symbiotic relationships are when two animals of different species live in close contact ... Glass sponges live in the deepest parts of the ocean and build intricate skeletons made of silica.

The two most prominent types of plankton in the ocean are zooplankton, which are tiny animal organisms, and phytoplankton, which are plantlike. (Other forms of plankton include bacterial and fungal.