Question

Explain general characteristics of phylum Platyhelminthes and Nematoda. Give two examples of each.

Answer 1

The basic characteristics of phyum Platyhelminthes are as follows:
1. The body is bilaterally symmetrical and dorsoventrally flattened.
2. These animals are triploblastic and lack a body cavity (acoelomates).
3. Respiratory system, circulatory system and skeleton is absent in these organisms.
4.These organisms are hermaphrodites, which means that both female and male reproductive organs are present in same individual.

Typical examples of organism belonging to phyum Platyhelminthes are Schistosoma (blood-fluke) and Taenia solium (pork tape-worm).

The characteristics of phylum Nematoda are as follows:
1. These organism are unsegmented, triploblastic, bilaterally symmetrical and pseudocoelomate animals.
2. Cilia is absent and body is covered by a tough covering called cuticle.
3. Separate sexes can be observed in this phylum.
4. Body is flattened, cylindrical and worm-like.

Examples of organism belonging to phylum Nematoda include Ancylostoma (hook-worm) and Enterobius (pinworm of humans).