Explain general characteristics of phylum Plathelminthes and Nematoda. Give two examples of each.
Explain general characteristics of phylum Plathelminthes and Nematoda. Give two examples of each.
(a) Characteristics of Platyhelminthes:
(i) Bilaterally symmetrical and dorsoventrally flattened animals.
(ii) Body is thin, soft, leaf-like or ribbon-like.
(iii) Digestive cavity (when present) with a single opening, the mouth (anus is absent).
(iv) Suckers and hooks are usually present.
(v) Circulatory and respiratory systems and skeleton are absent
(vi) Hermaphrodite i.e. both male and female reproductive organs occur in the same individual.
Example: Fasciola (liver-fluke) and Taenia solium (pork tape-worm).
(b) Characteristics of Nematoda:
(i) Bilaterally symmetrical, triploblastic, pseudocoelomate and unsegmented animals.
(ii) Body is worm-like, cylindrical or flattened.
(iii) Body is covered with a tough, resistant cuticle: cilia absent.
(iv) Sexes are separate.
(v) Most forms are parasitic but some are free-living in soil or water.
Example: Ascaris (round-worm) and Ancylostoma (hook-worm).
(a) Characteristics of Platyhelminthes:
(i) Bilaterally symmetrical and dorsoventrally flattened animals.
(ii) Body is thin, soft, leaf-like or ribbon-like.
(iii) Digestive cavity (when present) with a single opening, the mouth (anus is absent).
(iv) Suckers and hooks are usually present.
(v) Circulatory and respiratory systems and skeleton are absent
(vi) Hermaphrodite i.e. both male and female reproductive organs occur in the same individual.
Example: Fasciola (liver-fluke) and Taenia solium (pork tape-worm).
(b) Characteristics of Nematoda:
(i) Bilaterally symmetrical, triploblastic, pseudocoelomate and unsegmented animals.
(ii) Body is worm-like, cylindrical or flattened.
(iii) Body is covered with a tough, resistant cuticle: cilia absent.
(iv) Sexes are separate.
(v) Most forms are parasitic but some are free-living in soil or water.
Example: Ascaris (round-worm) and Ancylostoma (hook-worm).
