Question

Which of the following classes is characterized by the star-like body with arms sharply marked off from the central disc?
A. Ophiuroidea
B. Echinoidea
C. Holothuroidea
D. None of the above

Answer 1

Hint: As we knew the term nomenclature describes the names of organisms and naming of organisms according to their species and genus name. This is the classification of different species. Each species has different characteristics. Star fish or star bodies having a central disc belong to class Ophiuroidea. Some can be stingy and some are normal and not harmful.

Complete answer:
Option A: Ophiuroidea- Ophiuroidea has the structure of a star shaped body with arms marked and distinguished like branches. It can be called a star-fish.
Option A is the correct answer.
Option B: Echinoidea- echinoid is nothing but Echinodermata animals classified under Echinodermata are octopus, eels, sting fishes etc.
option B is not the correct answer.
Option C: Holothuroidea- holothurians are basement lived animals which lie in the sea surface. Examples can be sea cucumbers.
Option C is not the correct answer.
Option D: none of the above- this option is technically not available as one of the above-mentioned Option is correct.
Option D is the correct answer.

Hence, Option D is the correct answer.

Note:
Star-shaped or brittle star animals have $5$ branches which are perforated enough to grasp objects or stay in the sea bottom. They are bottom dwellers and perform commensalism too. Classification is a part of a taxonomic group, as taxonomic groups define a variety of categories to deal with animals based on their characters and size, basically morphology. All groups and classes of animals belong under taxonomy.