1.they have a leaf shape body and the body of these animals is soft and compressed from center.
2. There are about 20000 species of flat worms living in marine, freshwater and damp terrestrial habitats.
3. They are triploblastic acoelomate. There is development of a third layer, the mesoderm, which separates the ectoderm and endoderm.
4. Flatworms exhibit bilateral symmetry, and body is unsegmented.
5. They range in size from few millimeters to several meters.
6. Much of the body space is taken up by a branching sac type digestive system. Thedigestive system is poorly developed in some species or may be absent.
7. The excretory system consists of branching tubes ending in bulb like cells, the flame cells.
8. A well-developed nervous system is present in flatworms.
9. Respiratory and circulatory systems are absent.
10. The parasitic species absorb nutrients from the hosts. The free-living species feed on small animals and bodies of dead and decaying animals.
11. The free-living forms are motile. They move by cilia present on their undersides.
12. They reproduce by both sexual and asexual methods.
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characteristics
defining the product features/requirements for a software product will be left to customers or clients only
The defining features of a Barcalounger are deep padding allowing one to lounge back. They usually have leather material on the seat and wooden arms and frame.
It is built out of a frame that splits into two different sections. The Gladstone bag is deeper than a regular suitcase, being one of its defining features.
Modelz
Their fluffy white coats and smaller size are their defining features.
The correct spelling is Orangutan and it has a number of defining features. Perhaps the most notable feature is their reddish brown hair all over the body. Adult males have distinctive facial features around the cheeks and they use relatively sophisticated tools.
flatworm
yes, a spine is one of the defining features of what is a fish
Shapes and patterns, but no living creatures ('Graven images')
Shapes and patterns, but no living creatures ('Graven images')