The phylum Echinodermata , which contains about 6000 species, gets its name from the Greek, literally meaning "spiny skin." Many echinoderms actually do have "spiny" skin, but others do not. This phylum exists exclusively in the sea, and cannot be found on land or in fresh water.
<span><em>Whether living or non living:</em>
<em>When you put a sample of tissue under a microscope, if u can see a cell membrane, and can identify some cell structures like nucleus, mitochondria, vacuoles etc. , it was living, if not, its a non living thing.</em></span>
<span><em>However some cells don't have a nucleus( eg. prokaryotic cells), but all cells have a cell membrane or some sort of protective covering to contain the cell's insides. </em></span>
<span><em>To check if your specimen maybe-once living, maybe-still living "something", is living, get a look at it through an electron microscope - thats the best microscope ever- and see if the mitochondria's making any ATP( adenosine triphosphate, source of energy for most organisms), if it does, its living. If not, no</em></span><em>n living. :)</em>