To be alive an organism must be able to intake nutrients, respirate, grow, and reproduce
<em>both producers and consumers are the part of ecosystem but finally either directly or indirectly they become food of the decomposers that may be micro-organisms or the larger parasite or saprophyte ..
organisms taking food from living host are parasite while taking food from dead matter are saprophytes..</em>
Gravitational potential energy
A series of numbers is what you will need to look for to recognize a tatters.