Question

Hirudinaria and Pheretima are the representatives of the phylum
A)Cnidaria
B)Platyhelminthes
C)Annelida
D)Aschelminthes

Answer 1

Pheretima is a genus of earthworms which is mostly found in soil. Hirudinaria is known as cattle leech. It is free- living or living as parasites. They are invertebrates and are found in moist environments.

Complete answer:
To solve this question, we must know about the characteristic features of earthworms and leech.
The earthworm and leech are segmented worms found in the moist environment. The body is divided into short segments which are joined together as rings. They do not have legs or skeleton. The digestive system is closed with the mouth and anus. They have fluid filled cavity between the outer wall and the gut. Thus, they belong to the phylum Annelida.

Cnidaria-These are diploblastic aquatic animals. These animals have Cnidocytes which are distinct to the species and are used for catching prey. The body has radial symmetry and has tentacles. Example hydra and jellyfish.

Platyhelminthes- They are triploblastic, acoelomate, parasitic or free-living. They have excretory organs called the flame cells. The body is soft with the presence or absence of cilia. The distinguishing feature of this organism is the flat body. Example- flatworm.

Aschelminthes- These are called the round worms which are pseudocoelomates. They live in aquatic habitats. They are triploblastic with organ level of body organisation. They are endoparasitic in nature.

Hence, the correct answer is option (C)

Note: The excretory organ of Annelida is nephridia. It is found in pairs and functions similar to human kidneys. The function of nephridia is osmoregulation. It filters fluid from the coelom to a tubule.