Algae is a diverse group of aquatic organisms that have the ability to conduct photosynthesis. Certain algae are familiar to most people; for instance, seaweeds (such as kelp or phytoplankton), pond scum, or the algal blooms in lakes Plantae is a taxonomic group that includes land plants and green algae. ... Kingdom Plantae includes multicellular, (mostly) autotrophic eukaryotes that (usually) conduct photosynthesis. Kingdom is formerly the highest taxonomic rank or the most general taxon used in classifying organisms. Monera is a kingdom that contains unicellular organisms with a prokaryotic cell organization, such as bacteria. They are single-celled organisms with no true nuclear membrane. The Protista, or Protoctista, is a kingdom of simple eukaryotic organisms, usually composed of a single cell or a colony of similar cells. Protists live in water, in moist terrestrial habitats, and as parasites and other symbionts in the bodies of multicellular eukaryotes.
Paramecium is a unicellular organism with a shape resembling the sole of a shoe. It ranges from 50 to 300 um in size which varies from species to species. It is mostly found in a freshwater environment.
When plants and animals die, they become food for decomposers like bacteria, fungi, and earthworms. Decomposers or saprotrophs recycle dead plants and animals into chemical nutrients like carbon and nitrogen that are released back into the soil, air, and water.