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.
Most likely, yes! He most likely has inherited features that are similar to his uncle which can be through genes.
Classifying things by observation can best be done by using a : Taxon
Taxon divided organisms into different groups based on their unique similarities, which is the best way to classify things if you're doing it by observation.