Question

{"given":"The question asks for the special or defining characteristic feature of the phylum Coelenterata.","key_observation":"Coelenterates, also known as Cnidarians, derive their name from the presence of cnidoblasts or cnidocytes, which contain stinging capsules called nematocysts.","formula_steps":[],"option_analysis":[{"label":"(A)","text":"polymorphism","verdict":"incorrect","explanation":"Polymorphism is exhibited by some coelenterates (like Obelia) but is not a universal or defining feature of the entire phylum."},{"label":"(B)","text":"nematocysts","verdict":"correct","explanation":"Nematocysts (stinging cells) are the unique and defining characteristic of all coelenterates, used for anchorage, defense, and capturing prey."},{"label":"(C)","text":"flame cells","verdict":"incorrect","explanation":"Flame cells are the specialized excretory cells found in Platyhelminthes (flatworms), not in coelenterates."},{"label":"(D)","text":"hermaphroditism","verdict":"incorrect","explanation":"Hermaphroditism is a condition where both male and female reproductive organs are present in the same individual, which is seen in many phyla and is not unique to coelenterates."}],"answer":"(B)"}