Multiple choice

Which of the following phyla have true body cavity?

  1. Porifera

  2. Coelenterata

  3. Nematoda

  4. Annelida

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Annelida are the first phylum to exhibit a true coelom (a fluid-filled cavity completely lined by mesoderm). Porifera, Coelenterata, and Nematoda are acoelomate or pseudocoelomate.