👉Phylum Platyhelminthes🦠🦠🥖📖
👉Platyhelminthes have the following important characteristics:👇👇👇
They are triploblastic, acoelomate, and bilaterally symmetrical.
They may be free-living or parasites.
The body has a soft covering with or without cilia.
Their body is dorsoventrally flattened without any segments and appears like a leaf.
They are devoid of the anus and circulatory system but has a mouth.
They respire by simple diffusion through the body surface.
They have an organ system level of organization.
They do not have a digestive tract.
The space between the body wall and organs is filled with connective tissue parenchyma which helps in transporting the food material.
They are hermaphrodites, i.e., both male and female organs are present in the same body.
They reproduce sexually by fusion of gametes and asexually by regeneration by fission and regeneration. Fertilization is internal.
The life cycle is complicated with one or more larval stages.
They possess the quality of regeneration.
The flame cells help in excretion and osmoregulation.
The nervous system comprises the brain and two longitudinal nerve cords arranged in a ladder-like fashion.
Ex.-Planaria, OtoplanaFasciola hepatica, DiplozoonTaenia spp., Convoluta.
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