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