GENERAL HISTOLOGY

Detailed explanation-1: -Echinoderms have male and female reproductive organs in separate individuals and thus they are dioecious. Only a few of them are true hermaphrodites and can self-fertilize. So, statement (iii) is correct.

Detailed explanation-2: -Answer and Explanation: The correct answer is (b). Echinoderms do not have gills.

Detailed explanation-3: -Echinoderms are named for their spiny skin, which is covered by a thin layer of calcium carbonate plates and spines. Adult echinoderms have radial symmetry, but larvae have bilateral symmetry. Echinoderms have a unique water vascular system, with canals that extend along each body part.

Detailed explanation-4: -Echinodermata. Echinoderms are secondarily radially symmetric-their ancestors were bilaterally symmetric. The adult radial symmetry is pentamerous, with body parts occurring in fives or multiples of five.

Detailed explanation-5: -Echinodermata-Sea urchins, Sand dollars, Sea cucumbers, Seastars, Cushion stars, Brittle-stars, Basket-stars, Sea lilies, Feather stars–Discover Life mobile.