Answer:
Nematodes are referred to as "pseudocoelomates" since their coelom is not entirely lined with mesoderm ally cell - derived in most forms, and they are triploblastic.
<h2>What is a nematode?</h2>
Any unsegmented worm of the phylum Nematoda, having an elongated, cylindrical body; a roundworm
<h2>What are characteristics of the pseudocoelomate phylum?</h2>
<em>-bilateral symmetry, unsegmented, triploblastic</em>
<em>-body cavity a pseudocoel</em>
<em>-size: some microscopic, others a few meters in length</em>
<em>-body veriform</em>
<em>-complete gut (2 cavities)</em>
The structure of the body wall of pseudocoelomates explained:
<em>-muscles are longitudinal (no circular) beneath the hypodermis</em>
<em>-non-living cuticle secreted by the hypodermis</em>
<em>-composed of many layers of collagen</em>
<em>-useful for protection and containing high pressure of hydrostatic skeleton</em>
<em>-muscles contract and push against</em> fluid which causes movement
