Botany - B.E. Yakubenko 2017

Part Two. System of the Organic World
Chapter V. System of the Organic World

The organic world is remarkably diverse, and since ancient times, scientists have sought to organize knowledge about the living organisms surrounding them. In the Cytology/cytology/16.html">Early stages of civilization, a utilitarian approach prevailed, dividing living organisms into plants and animals. Plants were classified based on their useful properties—such as edible, poisonous, and medicinal—or categorized ecologically into meadow, marsh, aquatic, and forest plants.

During the time of C. Linnaeus, the living world was divided into two kingdoms: Plants and Animals. This division was used by taxonomists for quite a long time. Plants included not only Algae, spore plants, gymnosperms, and angiosperms, but also Fungi, Bacteria, and Lichens. In the middle of the last century, Fungi, Monera, and Viruses were separated into independent kingdoms from the Plant kingdom. The Fungi kingdom also encompasses lichens, which represent unique symbiotic associations between fungi and algae.

In the modern system, all kingdoms of Living organisms are grouped into two superkingdoms (domains) based on their cellular Structure: Prokaryotes (Pre-Nucleus) and Eukaryotes (Nucleated). There is no single consensus regarding the division of Prokaryotes into kingdoms; the authors follow the view of Academician A. Takhtajan (1974), who distinguishes a single prokaryotic kingdom—Monera (Monera)—comprising two divisions: Bacteria (Bacteriophyta) and Blue-green algae or Cyanobacteria (Cyanophyta). Viruses are also classified as a separate kingdom—Viruses (Vira).

The Classification of eukaryotes is likewise viewed differently among taxonomists. Due to the Introduction of novel Research Methods—foremost among them molecular biology—there is currently no single classification system universally accepted by botanists. This is due both to the inherent complexity of the evolutionary process and the ongoing, expanding research into individual plant groups. According to recent scientific data, the superkingdom Eukaryotes includes the following kingdoms: Chromista (Chromista), Protozoa (Protozoa), Fungi (Fungi, Mycota), Plants (Planthae), and Animals (Animalia).

The kingdoms Chromista and Protozoa include fungus-like organisms, of which we will examine representatives only from the divisions Plasmodiophoromycota and Oomycota. The Fungi kingdom comprises the following divisions: Chytridiomycota, Zygomycota, Ascomycota, Basidiomycota, and the artificial group known as anamorphic (imperfect) fungi. The Plant kingdom is divided into the subkingdom Lower Plants, which includes 9 to 13 divisions of algae (depending on the classification system), and Higher Plants, encompassing the divisions Bryophyta, Rhyniophyta, Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta, Gymnosperms, and Angiosperms.