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