BOTANY WITH THE BASICS OF HYDROBOTANY (AQUATIC PLANTS OF UKRAINE) - B.Ye. Yakubenko - 2011

VI. SYSTEM OF THE PLANT WORLD

LOWER SPORE PLANTS

GENERAL CHARACTERISTICS AND FEATURES

Class Trebouxiophyceae - Trebouxiophyceae

It predominantly unites unicellular, coccoid, and less commonly multicellular colonial, filamentous, heterotrichous, or lamellar Algae that grow under aerophytic, edaphic, or symbiotic conditions, as well as in fresh continental Water bodies. Approximately 300 species are confirmed to belong to this Class, of which about 200 are known in the flora of Ukraine.

They possess a three-layered Cellulose-pectin Cell wall with an intermediate (often absent) sporopollenin layer, a cruciate flagellar ROOT system with basal bodies displaced counterclockwise (the "11/5" configuration system). Cytokinesis occurs via cell plate formation involving a phycoplast, with the presence of semi-closed (exceptionally closed) mitosis and a metacentric spindle characterized by centrioles positioned laterally to the spindle.

Reproduction is asexual, via zoospores and autospores, and rarely vegetative through binary fission. At the same time, The formation of akinetes is also observed. The sexual process involves isogamy and oogamy, which are characteristic only of certain representatives.

Based on a combination of traits—primarily the type of morphological body Structure, Features of the reproductive process and mitosis, as well as the results of modern molecular-biological approaches—a Classification scheme of the class has been developed, distinguishing the following orders: Chlorellales, Trebouxiales, and Prasiolales.



Last update: 07/08/2026

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