Question

multiple choice question
animals that do not have true tissues are classified as _______, while animals that do have tissues are called eumetazoans.
radiata
parazoa
cnidaria
bilateria

Explanation:

• Radiata: These are animals with radial symmetry but they do have true tissues (e.g., Cnidaria which is a phylum within Radiata has tissues).
• Parazoa: Parazoans (sponges - phylum Porifera) lack true tissues. Their cells are loosely aggregated and do not form organized tissues.
• Cnidaria: Cnidarians are eumetazoans. They have two germ layers (ectoderm and endoderm) and form true tissues.
• Bilateria: Bilaterians are eumetazoans. They have three germ layers (ectoderm, mesoderm, endoderm) and well - defined tissues.

Answer:

Parazoa