Final answer:
The statement that medusas and polyps have similar body plans is true. They both belong to cnidarians and share a basic body organization, though they differ in form and lifestyle, with polyps being sessile and medusas being motile.
Step-by-step explanation:
While medusas and polyps are different in their physical appearance and lifestyle, they indeed share similar body plans. This is true. Both forms are part of the cnidarian group, and though they manifest with significantly different structures, the basic organization of their bodies is similar. They both have two tissue layers and a jelly-like substance called mesoglea in between these layers.
Polyps, such as sea anemones and corals, are generally sessile with a mouth opening facing upward, surrounded by tentacles. Conversely, medusas like jellyfish have a bell-like shape with their mouth and tentacles hanging downward. Interestingly, some cnidarian species can alternate between polyp and medusa forms within their lifecycle, showcasing the versatility of these body plans.
In summary, despite the distinct appearances of the polyp and medusa, their body plans are fundamentally similar, making the statement true. This is important both in understanding cnidarian biology and in recognizing how adaptable life can be when it comes to surviving in various marine environments.