They have a coelom, a space between the skin of the roundworm that allows the organs to move around freely by themselves.
Annelids are segmented whereas roundworms are not. Annelids have a true coelom while roundworms have a pseudocoelom. Annelids have a more complex nervous system than roundworms. Annelids have a more complex circulatory system than roundworms.
the reason earthworms are more complex than roundworms is b/c they have muscles 2 move with,and have a nervous system and a digestive system.
Mollusks exhibit greater complexity than roundworms in several key aspects, including their body structure and organ systems. Mollusks possess a more advanced and diverse body plan featuring a coelom, a muscular foot, and a mantle that can produce shells, whereas roundworms have a simpler pseudocoelomate structure. Additionally, mollusks often have specialized organ systems, such as a complex circulatory system and a nervous system with more developed sensory organs, enabling them to interact more effectively with their environment. This complexity allows mollusks to occupy a wider range of ecological niches compared to roundworms.
There's many of them, but here are some of the bigger ones; Annelids, unlike roundworms (or flatworms for that matter) are segmented. That is after all how they get their name (annelida = little ring). Annelids also have a very complex organ system. Roundworms only possess a reproduction system as they usually live in an organism's intestines and don't need to digest food. Annelids posses both a reproduction system, and a digestive system as well as a circulatory system. As they are true coelomates their organs and organ systems are organised rather than just kinda' being tossed in there. =)
Sucrose is more complex than glucose.
No a worm is more complex than a jellyfish
Far more complex.
Human cells are more complex than a paramecium. They are capable of doing more things than the single-celled paramecium.
Temperate forests are usually more complex with more layers of vegetation than taiga.
They are more complex because more nutrition is made throughout their body than the nutrition made in a diatom.
They are more complex because more nutrition is made throughout their body than the nutrition made in a diatom.
fugus, other nematodes, and anything bigger than it