SCIENCE
ZOOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an organism such as Planaria (flatworms) that have no body cavity
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an organism such as a jellyfish with a central digestive cavity
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an organism such as a mammal with a body cavity lined with 2 layers of mesoderm
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an organism such as a Nematode (roundworm) that has a “false” body cavity
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Detailed explanation-1: -Nematodes have a false body cavity and hence are called pseudocoelomate.
Detailed explanation-2: -Pseudocoelomate metazoans have a fluid-filled body cavity, the pseudocoelom, which, unlike a true coelom, does not have a cellular peritoneal lining. Most of the pseudocoelomates (e.g., the classes Nematoda and Rotifera) are small and none possess an independent vascular system. Muscular body and locomotor movements…
Detailed explanation-3: -The body cavity of nematodes is not lined by mesoderm. Hence pseudocoelom is found in nematodes.
Detailed explanation-4: -Nematodes are pseudocoelomate members of the clade Ecdysozoa. They have a complete digestive system and a pseudocoelomic body cavity. This phylum includes free-living as well as parasitic organisms. They include dioecious and hermaphroditic species.
Detailed explanation-5: -They have a fluid-filled body cavity separating the gut of the organism from the body wall but it is not lined by mesoderm, unlike true coelomates. All the organisms belonging to Aschelminthes are pseudocoelomates. Round worm ( Ascaris lumbricoides ) is an example of pseudocoelomate.