Question

question 2 of 25
which type of organism is the simplest?
a. sponges
b. vertebrates
c. chordates
d. deuterostomes

Explanation:

Sponges are among the simplest multicellular organisms. They lack complex organ systems, true tissues (in a strict sense compared to more complex animals), and have a relatively simple body plan. Vertebrates (like fish, mammals), chordates (which include vertebrates and some related groups), and deuterostomes (a major group that includes chordates and echinoderms) are more complex in terms of body organization, organ - system development, and evolutionary complexity.

Answer:

A. Sponges