Echinoderms lack respiratory and excretory systems.
Starfish and sea urchins are also echinoderms.
Starfish lack respiratory and excretory systems.
What is an example of an animal that lacks a respiratory and excretory system?

1: Dog
2: Human
3: alpacas
4: cacti
5: Starfish
6: Leeuwenhoek
7: Elephants
8: cows