Alaska Sea Grant
Simple one-celled or many celled plant-like organisms, usually living in the water, that can make their own food through photosynthesis. They do not have true roots, stems, or leaves like plants and belong to the kingdom Protista. They can be microscopic, one-celled organisms or many-celled organisms up to 100 feet long.
Alaska Sea Grant University of Alaska Fairbanks Alaska Department of Education and Early Development NOAA