[Campbell Biology P.740] Which of the following statements correctly differentiates between ... | Practice Question

Which of the following statements correctly differentiates between the polyp and medusa forms of cnidarians as described in the text?

  • A: Polyps are always motile, while medusae are always sessile.
  • B: Polyps adhere to the substrate by their oral end, while medusae are mouth-up.
  • C: Medusae are free-swimming and resemble a flattened, mouth-down version of the polyp, while polyps are largely sessile and cylindrical.
  • D: Only polyps possess tentacles for prey capture, not medusae.

Explanation

The text explicitly states that 'Polyps are cylindrical forms that adhere to the substrate by the aboral end of their body... and extend their tentacles, waiting for prey.' It also states that 'A medusa plural, medusae resembles a flattened, mouth-down version of the polyp. It moves freely in the water by a combination of passive drifting and contractions of its bell-shaped body.'