Some bacteria and plants use carbon dioxide as their source of gas to survive.
Flatworms (apart from the turbellarians, (planarians are in the class turbellaria)) are parasitic and don't need complex nervous systems. A parasitic animal devotes much of itself to reproduction and doesn't worry about other tasks. Cestodes don't even have a gut, they absorb food via diffusion through their skin. Annelids are free-living animals, and they need to move around more. They don't spend their adult life hooked to the inside of an animal, they move around, and need a more complex nervous system to give them a better view of their world.
Answer:
I Think this
directly provide leaf cells with the water involved in photosynthesis
Explanation:
