Epiphytes on tropical forest trees:
Trees of tropical forests- receives neither help nor harm
Epiphytes- receives minerals and substrate from the trees
Remoras riding on sharks:
Remora- can transport easier and even receive food from shark
Shark- unaffected by transporting the remora
Monarchs storing milkweed's poison:
Monarch butterfly- stores poisonous chemical from the milkweed that prevents predators from attacking/ consuming the butterfly
Milkweed- is unaffected when buttefly takes some of its poison