[Campbell Biology P.1135] An animal is observed to have a diffuse network of interconnected n... | Practice Question

An animal is observed to have a diffuse network of interconnected neurons throughout its body, without a centralized brain or distinct nerve cords. Which type of animal, as described or depicted in Figure 49.2, is most likely to possess this nervous system organization?

  • A: A planarian, due to its simple body plan.
  • B: A sea star, characterized by its radial symmetry and a central nerve ring.
  • C: A hydra, as it represents one of the simplest animals with a nervous system.
  • D: A salamander, an example of a vertebrate with a complex nervous system.

Explanation

The text states that 'Hydras, jellies, and other cnidarians are the simplest animals with nervous systems. In most cnidarians, interconnected neurons form a diffuse nerve net Figure 49.2a '. This description perfectly matches the animal in question.