drifting or wandering
plants
microscopic
aquatic (water-living)
zooplankton
phytoplankton
eukaryotes
prokaryotes
All plankton are microscopic (too small to see without a microscope).
Millions of cells
A few dozen cells
Hundreds of cells
Thousands of cells
Zooplankton are tiny animals.
the ocean
algae
it makes the water more acidic.
it makes the water saltier.
it kills large predators like sharks.
Just for fun
To see in the dark
To scare away predators
To attract a mate