We know for sure that both plants and animals are living organisms because they fulfill all the basic characteristics necessary for life; These are
We have organisms that are neither plant nor animals, yet are living. In fact, anything that has life must belong to one of the following kingdoms:
Kingdom MONERA (All bacteria and Blue-green algae belong here)
Kingdom FUNGI (All fungi belong here)
Kingdom PLANTAE (All plants belong here)
Kingdom ANIMALIA (All animals belong here)
Protists are neither plants nor animals nor fungi nor bacteria; they are simply protists. (An organism belonging to kingdom protista is referred to as protists; just as those belonging to kingdom plantae are called plants).
All protists are eukaryotic organisms (being eukaryotic imply that their cell structure has a nucleus bordered by a membrane. They also have organelles in their cytoplasm). Generally, they live in an aquatic or fluidly or moist habitat. All protists do not share similar characteristics since some are animal-like (they have animal like features, for instance, their cells have a cell membrane and mitochondria) while some behave like plants because they have cell wall and chloroplast, and as a result, can manufacture their own food. A few protists are fungi-like because these reproduce by forming spores.
Generally, all protists are commonly grouped together because they do not particularly fit into any other kingdom. Examples of protists includes amoeba, paramecium, euglena, chlamydomonas, plasmodium, kelp, slime molds and water molds.
Note: Some protists are single celled (unicellular) while others are colonial (form colonies) or multicellular (made up of more than one cell). Some appear to be very large, for instance kelp while others can be free-living (for example, amoeba) or parasitic (for example, plasmodium).
This is the ability of an organism to move from one point to another. Although some protists are non-motile (cannot move from one point to another), others exhibit locomotion via a variety of locomotary organelles.
Below are some protists and their locomotary organelles;
Example of non-motile protist are plasmodium and Toxoplasma gondii.
Note: slime mold and water mold are protists that exhibit little movement.
Some are photosynthetic autotrophs (that is, they can manufacture food from sunlight energy). Examples are euglena and algae.
Some are heterotrophic (that is, they cannot produce their own food and hence rely on readymade food). Examples are amoeba and paramecium.
Note: Some protist are both autotrophic and heterotrophic. Euglena is an example.
Most are unicellular. Amoeba, paramecium, euglena, chlamydomonas and plasmodium are examples of unicelluler protist.
A few protist are multicellular, for example kelp, slime molds and algae.
Reproduction is typically asexual but sometimes, sexual reproduction does occur. Binary fission is a form of asexual reproduction that occurs in Amoeba. Plasmodium falciparum may undergo sexual reproduction at some stages in it's life cycle.
They generally live in an aquatic habitat.
Their cells have a well defined nucleus and cell membrane.
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