Question

Characters of phylum are given below. Read those carefully and name the phylum.
A. Spines of calcium carbonate are present on the body
B. These animals are exclusively marine.
C. They perform the locomotion with the help of tube feet
D. Their skeleton is made up of calcareous plates or spicules

Answer 1

Hint: The characteristic mentioned above like exclusively marine, perform locomotion by means of tube feet, have spines covering their body that are made of calcium carbonate, and have a skeleton made of calcareous plates are all refer to phylum Echinodermata.

Complete answer:
Definition- Phylum Echinoderm is the usual name given to any member of marine animals.
They show the following characteristics -
A. Habitat: The echinoderms are exclusively marine. Most of them are found lying bottom along the shoreline in the shallow sea.
B. Body wall: Their body is covered by a delicate membrane. The mesodermal cells develop a firm calcareous exoskeleton. This exoskeleton is also known as an endoskeleton.
C. Body from: They are triploblastic as well as coelomate. Their mouth is found on the lower or oral surface. The anus is found on the upper or oral surface.
D. Symmetry: The larvae of echinoderms displays bilateral symmetry. But the adult 3 show radial symmetry. It’s an adaptation for their mode of living.
E. Shape: The body of Phylum Echinodermata
Flattened like biscuit e.g. Cake urchin.
Star-shaped with short arms like Starfish.
Star-shaped with long arms that is a Brittle star.
Globular for instance Sea urchin.
Elongated: has no central disc from which arms radiate e.g. Sea Cucumber.

So, the correct answer is Echinoderm.

Note: The phylum Echinodermata includes about 7000 living species, resulting in the second-largest grouping of deuterostomes. Echinoderms are also considered as the largest phylum that has no freshwater or terrestrial-based representatives.