I can't give you a harmful one, but a helpful one is a leech. They create a chemical that stops blood from clotting. Doctors use it after surgery to keep swelling down, which also helps prevent swelling.
Bacteria can be both harmful and helpful
They are helpful because they clean out intestines. they are harmful because they can cause diseases
Bacteria can be helpful by deleting bad viruses and harmful by killing you
Jelly Fungi is Helpful.
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I can't give you a harmful one, but a helpful one is a leech. They create a chemical that stops blood from clotting. Doctors use it after surgery to keep swelling down, which also helps prevent swelling.
it can be helpful or harmful
sometimes they are helpful and harmful.
Decomposers are important because they break up waste and dead material.
Bacteria can be both harmful and helpful
Sandpaper is both helpful and harmful.
they are helpful not harmful to plants
harmful
Depends on what part of "harmful" or "helpful" you are referring to.
helpful
Helpful