Dictionary > Protista

Protista

Definition
noun
A taxonomic kingdom in old system of classification (i.e. five kingdom scheme), comprised of species (referred to as protists) characterized by being eukaryotic, mostly single-celled (others multicellular or colonial), and lacking specialized tissue organization
Supplement
Kingdom Protista is one in the five kingdom scheme of classification. This method of classification is regarded as old and is used formerly to classify organisms (as proposed by Robert Whittaker1). In this system of classification, Protista is comprised of animal-like (protozoa) and plant-like (algae) eukaryotes. Accordingly, Protista is divided into several phyla. In particular, animal-like protists are divided into the following phyla: Sacordina (protists that move using pseudopod), Mastigophora (protists that move using flagella), Ciliaphora (protists that move using cilia), and Sporozoa (protists that form spores). As for the plant-like protists (Subkingdom Phycobionta), there are also various phyla: Euglenophyta (euglenids), Chrysophyta (diatoms), Pyrrophyta (dinoflagellates), Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae). The Cyanophyta or blue-green algae, which are prokaryotic organisms, are traditionally included in this group but later on they were grouped together with bacteria under Kingdom Monera. Fungus-like (i.e. slime molds and water molds) are also included in Kingdom Protista.
The general characteristics of protists are as follows: most of them live in aquatic habitats, simple eukaryotes lacking specialized tissue organization, many are single-celled, although there are protists that form colonies or are multicellular.
It should be noted, however, that the taxonomic classification of organisms is bound to change as further studies of the species would lead to newer system of classification, such as that in The NCBI taxonomy database.2
Related term(s):

Mentioned in:

  • Kingdom
  • Slime mold
  • Water mold
  • Protozoa
  • Reference(s):

    1 Brown, E G. 2009 Feb 2. Providencia Infections. New York (NY): WebMD LLC Medscape.com.

    2 The NCBI taxonomy database. Retrieved from http://www.ncbi.nlm.nih.gov/taxonomy.


    You will also like...

    squirrel
    Animal Water Regulation

    Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

    Plant Water Regulation
    Plant Water Regulation

    Plants need to regulate water in order to stay upright and structurally stable. Find out the different evolutionary adap..

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Adaptation Tutorial
    Adaptation Tutorial

    Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

    Plant biology
    Plant Biology

    Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

    Early Earth
    The Origins of Life

    This tutorial digs into the past to investigate the origins of life. The section is split into geological periods in the..

    Related Articles...

    No related articles found

    See all Related Topics