what mostly have a more complex nervous system?
nerve cells protist animals without backbone remains of prehistoric life members of their own species sensory neurons Veins and arteries. bacteria
A B C D E F G H
Invertebrates are animals without a backbone.
most animals without a backbone have a more complex nervous system
what mostly have a more complex nervous system? (A) nerve cells (B) protist (C) animals without backbone (D) remains of prehistoric life (E) members of their own species (F) sensory neurons (G) Veins and arteries. (H) bacteria