Do flatworms have tissue or systems?

Flatworms are considered to have a simple level of tissue organization, possessing three primary germ layers: ectoderm, mesoderm, and endoderm. They have a relatively simple body structure without specialized systems like those found in more complex animals. Instead of a circulatory or respiratory system, flatworms rely on diffusion for the transport of nutrients and gases. Additionally, they have a basic nervous system and muscular tissues, allowing for movement and response to their environment.