How is the body profile of Platyhelminthes (flatworms) distinctly described?
Answer
Unsegmented and flattened from top to bottom (dorsoventrally)
The phylum Platyhelminthes, known commonly as flatworms, exhibits a body shape that contrasts significantly with other worm groups. Their structure is characterized by being distinctly unsegmented, meaning they lack the repeating divisions seen in annelids. Furthermore, they are flattened along the dorsal-ventral axis, meaning they are compressed from the top surface to the bottom surface. This characteristic flattening results in a visual appearance often described as ribbon-like, distinguishing them clearly from the cylindrical nematodes or the segmented earthworms.
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