Describe phylum Platyhelminthes.

(N/A) $\rightarrow$ Platyhelminthes have a dorso-ventrally flattened body,hence they are called flatworms.
$\rightarrow$ These are mostly endoparasites found in animals,including human beings.
$\rightarrow$ Flatworms are bilaterally symmetrical,triploblastic,and acoelomate animals with an organ-level of organization.
$\rightarrow$ Hooks and suckers are present in the parasitic forms.
$\rightarrow$ Some of them absorb nutrients from the host directly through their body surface.
$\rightarrow$ Specialized cells called flame cells help in osmoregulation and excretion.
$\rightarrow$ Sexes are not separate (hermaphrodites).
$\rightarrow$ Fertilization is internal,and development occurs through many larval stages.
$\rightarrow$ Some members like Planaria possess high regeneration capacity.
$\rightarrow$ Examples: Taenia (Tapeworm),Fasciola (Liver fluke).