Botany - Animal Kingdom Question with Solution | TestHub
Bilaterally symmetrical and acoelomate animals are exemplified byNEET 2020 (Phase 1)
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Answer:
Solution:
Coelom: The body cavity; which is lined by mesoderm is called coelom.
Coelomates: If coelom is present, the animal is called coelomate, e.g. Annelids, Molluscs, Arthropods, Echinoderms, Hemichordates and Chordates.
Pseudoceolomates: If the body cavity is not lined by mesoderm, but the mesoderm is present as scattered pouches in between the ectoderm and endoderm, the animal is called pseudocoelomate, e.g. Aschelminthes.
Acoelomates: When the body cavity is absent, the animal is called acoelomate, e.g. Platyhelminthes.
SYMMETRY:
Some animals are almost asymmetrical. Their body cannot be divided into two equal halves from any plane, e.g. sponges.
Radial Symmetry: In the case of radial symmetry, any plane passing through the central axis divides the body into two identical halves, e.g. Coelenterates, Ctenophores, Echinoderms, etc.
Bilateral Symmetry: In the case of bilateral symmetry, the body can be divided into two identical halves only through a single plane, e.g. Platyhelminthes, Annelida, Arthropoda, etc.
