Write the general characteristics of Aschelminthes.

(N/A) $\rightarrow$ Phylum Aschelminthes (also known as Nematoda) includes roundworms.
$\rightarrow$ They are commonly called nematodes.
$\rightarrow$ The body of Aschelminthes is circular in cross-section, hence the name roundworms.
$\rightarrow$ They may be free-living, aquatic, terrestrial, or parasitic in plants and animals.
$\rightarrow$ Roundworms exhibit an organ-system level of body organization.
$\rightarrow$ They are bilaterally symmetrical, triploblastic, and pseudocoelomate animals.
$\rightarrow$ The alimentary canal is complete with a well-developed muscular pharynx.
$\rightarrow$ An excretory tube removes body wastes from the body cavity through the excretory pore.
$\rightarrow$ Sexes are separate (dioecious), i.e., males and females are distinct. Often, females are longer than males.
$\rightarrow$ Fertilization is internal, and development may be direct (the young ones resemble the adult) or indirect.
$\rightarrow$ Examples: Ascaris (Roundworm), Wuchereria (Filarial worm), Ancylostoma (Hookworm).