What do phytoplankton do? a) produce toxins that can be lethal to humans and fish who ingest it. b)provide food for a large range of marine life and supply much of Earth's oxygen. c)play a role in recycling organic matter in water. d)sweep food into oral grooves and down into a food vacuole.
The answer is b. This can be remembered if you know that photosynthesis creates oxygen. Just remember that 'phytoplankton' starts with 'ph' just like 'photosynthesis', and you'll know that phytoplakton also create oxygen.
