An undifferentiated cell of a multicellular organism which is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation.
The answer is:
Echinodermata
The word echinodermata is Greek which literally means "Spiny Skin". Echinodermata is a phylum under kingdom animalia. Not all of them have spiny skins, but most of them do. Other characteristics would be their radially symmetric body. They have appendages that grow outward from the center. Examples of echinoderms would be sea stars and sea urchins.
A grow and divide uncontrollably.
If you have one sickle cell gene, you have sickle cell trait and you will not develop the sickle cell disease. If you inherit two sickle cell genes, you have sickle cell anemia.