Question

A speciality of echinoderms is the presence of ____________.
A. Both epidermal exoskeleton and mesodermal endoskeleton
B. Ciliated epidermis
C. Coelom
D. None of these

Answer 1

Hint: Echinoderms belong to phylum Echinodermata which are exclusively marine. Echinodermata are multicellular organisms with an organ level of organization.

Complete answer:
Echinoderms are colorful and are of different shapes that can be found deep inside the sea and also in the intertidal areas of the sea. Epidermis of echinoderms forms the exoskeleton whereas the mesoderm forms the endoskeleton.
Water vascular system in Echinoderms is responsible for breathing, excretion, and circulation.
Echinoderms do not show metameric Segmentation and the head of echinoderms is present on the ventral side and the anus is present on the dorsal side of the body. Tube feet are used by echinoderms for movement and locomotion.

Option(A): Epidermal exoskeleton and mesodermal endoskeleton are considered as special features of Echinoderms.

Option(B): Ciliated epidermis is a characteristic which can only be seen in limited members of phylum Echinodermata.

Option(C): Coelom is present in all echinoderms but this is not a special feature as it can also be seen in Annelids, Arthropods, Mollusca, Hemichordates, and chordates.

Option(D): One of the above options is correct.

Hence, the correct answer is option (A)

Note: 1.The skin of echinoderms show some small spine-like structure
2.Echinoderms have an open circulatory system and are the triploblastic organism with a coelom cavity.