Question: Nematodes are placed in the Phylum…
Options:
Nematoda
Annelida
Aschelminthes
None of the above
Nematodes, also known as roundworms, are classified under the phylum Nematoda. This phylum is characterized by unsegmented, cylindrical worms with a tough outer cuticle. Nematodes are incredibly diverse, with over 25,000 described species, and they occupy a wide range of habitats, including soil, freshwater, marine environments, and even as parasites in plants and animals.
📌Other Options Explanations:
b) Annelida: Annelids are segmented worms, including earthworms and leeches. They have a distinct body structure with repeating segments.
c) Aschelminthes: Aschelminthes was a previously used phylum that included several groups of worms, including nematodes. However, due to advances in understanding their evolutionary relationships, this phylum is no longer considered valid.
• Related Terminologies:
Phylum: A taxonomic rank used in biological classification to group organisms with similar body plans and evolutionary history.
Cuticle: The tough, flexible outer covering of nematodes.
Parasite: An organism that lives in or on another organism (host) and benefits by deriving nutrients at the host's expense.
🔑Key Points:
Phytophagous refers to the organisms that feed on plant or plant materials.
Nematodes belong to the Phylum Nematoda.
The body of the nematodes is circular incross-sections thus they are commonly known as roundworms.
They are bilaterally symmetrical, triploblastic, and pseudocoelomate organisms showing an organ-system level of body organization.
They have distinct mouth and anus, and the alimentary canal is complete with a well-developed muscular pharynx.Â
Nematodes are dioecious i.e., males and females are distinct.
They lack the circulatory system and respiratory system.
Examples- Ascaris (Round Worm), Wuchereria (Filaria worm), Ancylostoma (Hookworm), Trichinella, Spirura, etc.
🛑 Additional Information::
Nematodes may be free-living, aquatic, terrestrial, or parasitic in plants and animals.
Parasitic nematodes cause diseases in the host.
The majority of phytophagous nematodes are root parasites.
The most economically significant group of plant parasite nematodes are root-knot nematodes and they develop neoplastic feeding sites in the roots of their host plants.
Some examples of root parasitic nematodes are Trichodorus, Meloidogyne, Xiphinema (dagger nematodes), etc.
Root parasitic nematodes are found worldwide, and are obligate parasites of the roots of various species of monocotyledonous and dicotyledonous, herbaceous, and woody plants.
These parasites may be ectoparasites or endoparasites of the plants.