2 résultats pour "cnidarians"
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Cnidarians - biology.
small, inconspicuous polyps. Polyps reproduce asexually to form a medusa—saucer-like structures bud off the polyp and swim away as new medusae. C Cubozoa The medusa phase dominates in animals in the Cubozoan class. Cubozoan medusae are commonly called box jellies because they have a cube shape with a singletentacle or group of tentacles hanging from each corner at the mouth end of the animal. The Cubozoan polyp is small and inconspicuous and an entire polyp transformsinto a medusa in a type of...
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Comparative Anatomy.
In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...