Aim of the course: The aim is to provide knowledge on diversity and evolutionary history high taxa at domain, kingdom and phylum level. The course presents information on history of megaclassification, morphological, cytological and ecological features of all domains of living beings, as well as kingdoms and phyla of eukaryotes.
Short description of the taught discipline: As humankind grew accustomed to a great variety of the living beings, a need arose to assort them. Principles of classification largely differ and three main schools of thought can be distinguished. Part of the authors follow Aristotle and acknowledge existence of not more than two kingdoms of the living beings, and certain authors perceive biodiversity through numerous kingdoms. Nevertheless, none of the up-to-date classification systems assumes an existence of only two kingdoms. In addition, a taxonomic category beyond a level of kingdom – dominion or domain – is being used by some researchers.
History of megaclassification can be divided into four periods. The first period is characterized by the use of predominantly external morphological characteristics of the living beings. During this period, main instruments for the analysis of biological characteristics were binocular magnifier and light microscope. This period lasted until the invention of an electron microscope. In the course of the second period, by means of electron microscopy the common nature of the living beings progressively became more obvious on the cellular level. During the third period, biochemical and molecular characteristics of the living creatures were taken as basis for interpretation of evolutionary associations. At the beginning of the 21st century, the question of life definition was re-posed, starting the fourth period of megaclassification history. The landmark of this period is not only systematization and rather superficial interpretation of facts obtained by instrumental methods, but also an attempt to comprehend a multitude of discrete data in the most general fashion, taking on elements of philosophy. In particular, this question relates to the dilemma: whether viruses exist as the living beings, or they are representing forms of inorganic matter. Novel discoveries in the area of virology challenged the opinions of most authors that had for more than two decades ignored viruses while composing classification systems of the living world.
Understanding that the postulate about cells being the only elementary structural units had no substantial ground brought about the nucleic acids as criteria for differentiating the living creatures from the non-living matter. Nevertheless, the prions as protein particles with no nucleic acid content are capable of changing and reproducing. No other natural body without nucleic acid is able to evolve or reproduce. Due to these features, prions may be considered as the living beings. It is obvious that the viroids, virusoids and viruses share a number of common characteristics, whereas the prions reproduce in an entirely different fashion. Additionally, prion structure is uncommon to that of other acellular organisms that contain nucleic acid. It can therefore be assumed that the evolutionary origin of prions is not connected with the origin of other acellular organisms.
Differences between prions and the rest of acellular organisms are comparable to those between the nucleic-acidcontaining acellular organisms and the cellular life forms. Namely, three large groups of the living beings exist: acellular organisms without nucleic acid, acellular organisms with nucleic acid, and cellular organisms. Regarding these three groups as dominions would be logical; however, since the cellular organisms comprise an immense number of species, practical reasons speak in favour of the five-dominion classification of the living beings: Prionobiota (acellular organisms without nucleic acid), Virusobiota (acellular organisms with nucleic acid), Archaebiota (organisms with prokaryotic structure that show many differences in their biochemistry and in genome from all other forms of life), Bacteriobiota (typical prokaryotic organisms), and Eukaryobiota (eukaryotic organisms).
Topics of lectures and seminars:
Topic 1. History of living being concept (seminar)
Topic 2. History of megaclassification: two and three kingdom systems (lecture)
Topic 3. History of megaclassification: multikingdom systems (lecture)
Topic 4. History of megaclassification: three domain systems (lecture)
Topic 5. History of megaclassification: five domain system (lecture)
Topic 6. Nature of eukaryotic cell (seminar)
Topic 7. Kingdom Protozoa (lecture)
Topic 8. Kingdom Chromista (lecture)
Topic 9. Kingdom Chromista - selected groups of Hacrobia (seminar)
Topic 10. Kingdom Chromista - selected groups of Alveolata and Rhizaria (seminar)
Topic 11. Kingdom Plantae (lecture)
Topic 12. Kingdom Fungi (lecture)
Topic 13. Kingdom Animalia (lecture)
Topic 14. Microsporidia (seminar)
Topic 15. Chytridiomycota (seminar)
Topic 16. Ctenophora (seminar)
Topic 17. Myxozoa (seminar)
Topic 18. Vampyrellidea (seminar)
Duration of academic discipline (course): 18 hours of lectures and 18 hours of seminars
Forms of checking the student's progress: seminars and final exam
Maximum points (percent): 100 points (100%)
Constituents in the final rating of mastering the course, points (%): attending classes is obligatory, active work at the seminars (50 points, 50%), final test (50 points, 50%). Scores of 55 points (55%) are sufficient to pass the exam.
List of recommended literature:
1. Archibald J.M., Simpson A.G.B. and Slamovits C.H. (editors). 2017. Handbook of the Protists (2nd edition). Springer, Cham.
2. Margulis L. and Chapman M.J. 2009. Kingdoms & Domains: An Illustrated Guide to the Phyla of Life on Earth (4th edition). W.H. Freeman and Company.
Supplementary educational and methodological literature:
1. Ingold C.T. and Hudson H.J. 1993. The Biology of Fungi (6th edition). Chapman & Hall, Torquay.
2. Petersen J.H. 2013. The Kingdom of Fungi. Princeton University Press, Princeton.
3. Gnanam C.R. 2013. Introduction to Mycology. MJP Publishers, Chennai.
4. Graham L.E. and Wilcox L.W. 2000. Algae. Prentice Hall, Sydney.
5. Lee R.E. 2018. Phycology (5th edition). Cambridge University Press, Cambridge.
6. Sharma O.P. 2011. Algae. Tata McGraw Hill, New Delhi.
7. Schierwater B. and DeSalle R. (editors). 2022. Invertebrate Zoology: A Tree of Life Approach. CRC Press, Boca Raton.