Question

Flatworms are similar to cnidarians in that both ______.

A. have pseudocoeloms
B. have true tissues
C. lack a gastrovascular cavity
D. exhibit bilateral symmetry
E. include many parasitic species

Answer 1

Flatworms and cnidarians both exhibit bilateral symmetry, allowing for a distinct head region and efficient movement and coordination.

Step-by-step explanation:

Flatworms, also known as phylum Platyhelminthes, share the characteristic of exhibiting bilateral symmetry with cnidarians. This means that both flatworms and cnidarians have a body plan that can be divided into two mirror-image halves along a central axis. This type of symmetry enables flatworms and cnidarians to have distinct head regions and allows for more efficient movement and coordination.

One example of bilateral symmetry in flatworms is the presence of a distinct head region that includes nerve cells and sensory organs, such as eyespots. This head region, known as cephalization, allows flatworms to have a concentrated sensory and nervous system, which aids in responding to their environment. Cnidarians, on the other hand, have radial symmetry, meaning that their body parts are arranged around a central point, like the spokes of a wheel.