(self-stable enclosed ecosystem)I need to make an ecosystem in my biology class. The trick is, I cant open it.. It is enclosed and has to have something living in such as a fish or worm or plant. I cant feed them or water them. I have to have it in a 2 litters bottle. This has to survive for months, if the living things die over that time the best grade I can get is a B-.. I need to get a good grade on this project and need ideas that will work. I have an idea but i dont know if it will work, let me know what you think: I will close off a quarter of the bottle and fill it with water. I will have a water basted plant living in it. The rest of the bottle will be filled with dirt/compost/a wet sponge, in there I will put several worms. The worms will breath out what the plant will breath in and in return the plant will breath out what the worms will breath in. The water and plant will condensate the bottle and keep it moist for the worms.

I think that will work but you have a better idea, PLEASE let me know!

Also my teacher said fungus and things like do not count.. She thinks its cheating.