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