Question

Which of the following statements is false?

a. Eumetazoans have specialized tissues and parazoans don’t.

b. Lophotrochozoa and Ecdysozoa are both Bilataria.

c. Acoela and Cnidaria both possess radial symmetry.

d. Arthropods are more closely related to nematodes than they are to annelids.

Short answer

In Acoela, no coelom is present and shows bilateral symmetry. Cnidaria falls under the category of Radiata and shows radial symmetry.

Step-by-step solution

Step 1. Introduction

Animal phylogenetic trees are constructed using genetic, fossil, and morphological data. Due to the lack of Hox genes in this group, the Ctenophora and Porifera are both regarded as basal, though it is still unclear how these two taxa relate to one another or to the "Parahoxozoa" (Placozoa + Eumetazoa).

Step 2. Explanation for the correct option 

The final answer to this question is c. Acoela and Cnidaria both possess radial symmetry.

In Acoela, no coelom is present and shows bilateral symmetry. Cnidaria falls under the category of Radiata and shows radial symmetry.

Step 3. Explanation for the incorrect options 

Parazoa is organisms with no tissue whereas Eumetazoa has specialised tissues. Lophotrochozoa and Ecdysozoa both fall under the category of Bilataria and therefore show bilateral symmetry. Arthropods and Nematodes fall in the category of Ecdysozoa and are therefore more closely related. Annelida falls in Lophotrochozoa and is therefore not closely related to Arthropoda.