In this section, we will focus on the classification of microorganisms which is included in the classification of living organisms in general. In order to study the classification of organisms, we will start with taxonomy and then focus on the hierarchical systems, the nomenclature And finally, the phyla in the domains bacteria and archaea is another outline for taxonomy. We will look at the initial five kingdoms and then the classification attempts. As more organisms were being discovered, and the structural and physiological details of the same were being discovered as well. And we will also see how these five kingdoms were then regrouped into Three current domains. The initial five kingdoms were the planter animalia, protista, monera and the fungi.

In the next slide, let us see how these kingdoms came about. During the 18th century, Karl also known as carolus Linnaeus found similarities in the form of two kingdoms and named them as legit Dahlia and animalia. The similarities were that both were multicellular. But what about unicellular organisms? Well, in 1866, Ernest heco, the German biologist and physician created a third Kingdom the kingdom protista. Although no longer renews the king protista included micro organisms that fit into neither animal or plant kingdoms at that time, the kingdom protista included bacteria.

In 1931, the first prototype of an electron microscope was constructed in 1937. Edward Chateau notice that within the protester there were organisms with prokaryotic and eukaryotic features. By the 1950s, scientists discovered that some products had a nuclear membrane while others did not. Therefore, in 1956, Herbert copelan placed bacteria that is microorganisms without a nucleus into a fourth kingdom, the kingdom monera. The Kingdom protista was later modified to separate prokaryotes into the separate kingdom of monera, leaving the protest as a group of eukaryotic organisms while the kingdom monera would be for prokaryotic organisms. In 1959 Robert Whittaker found that fungi originally in the plants Kingdom had an absorb to more of nutrition different from that of plants.

Thus a fifth kingdom was formed the kingdom fungi. These five kingdoms remained the accepted classification until the development of molecular phylogenetics in the late 20th century. In 1970s, car rules, based on the molecular analysis of ribosomal RNA showed a dichotomy within the prokaryotes. Therefore, in 1990, the kingdom Minerva was actually separated into two domains the domain of bacteria and the domain archaea. So here is a very good concept map that takes us through time in history showing how the classification of living organisms change from the initial high kingdoms to the current concept of so 12345 kingdoms to the current concept of three domains around 1735 Carlos Linnaeus plays living organisms into either one of two kingdoms as I mentioned before the Italia or the animalia. The Kingdom as Italia consisted of plants and fungi initially, whereas the kingdom animalia consisted of the protozoa and animals.

In 1866, algae fungi and protozoa were combined into a group the kingdom protista was planted and animalia remained the same. Then, in 1937, based on structure and metabolism cells were divided into either prokaryotes or eukaryotic cell structures. In 1959, the appropriate form the kingdom monera, whereas the eukaryotic form the kingdoms protista, fungi and Amalia and plant a, thus forming the five kingdoms as we know, in 1990, based on molecular analysis, the kingdom monero was further divided It as vigor domains, known as the domain bacteria and the domain archaea, and the rest of the four kingdoms were placed into the domain eukarya to represent the eukaryotic cell structure. Here are the current feed domains depicted in the classification of living organisms in this graph. The three domains are the domain bacteria, archaea and eukarya. In terms of kingdoms within the domain bacteria is the kingdom eukarya.

Meaning crew bacteria and within the domain archaea is the kingdom archaea bacteria meaning ancient bacteria. Now within the domain eukarya is our there is four kingdoms that are the protista fungi plant a and animalia. Why microorganisms within the domain bacteria and archaea are prokaryotic in cell structure, those of eukarya domain eukarya are of course, eukaryotic in terms of the cell structure, why bacteria have cell wall with peptidoglycan. archaea do not as we had seen before they have episode of FTD like and cell walls and the kingdom protista has cell walls of cellulose and some have chloroplasts resembling the cell wall of plants. The kingdom, fungi have cell walls made up of kitten. And the family of course have neither cell walls nor chloroplasts.

In terms of the number of cells, bacteria and eukarya are unicellular microorganisms whereas protista are mostly unicellular, with some being multicellular. In the fungi On the contrary, most are multicellular and some unicellular plants and animals are of course multicellular in terms of mode of nutrition autotrophs can make their own food whereas hetero autotrophs cannot. The teen and archaea are either autotrophs or heterotrophs protista are also either auto or heterotrophs. Whereas fungi, plants and animals are all heterotrophs. Meaning they need to obtain food from external sources for energy. Finally, to name a few examples streptococcus and Sherry Shere cola are examples of bacteria Of course, methanogens and hollow files, examples of archaea, Amoeba paramecium and giant kelp.

Examples of protest mushrooms and yeast examples of fungi, Moses farms and flowering plants are in the kingdom planted. sponges, worms, insects, fish and animals are all included in the kingdom animalia So in summary, based on these observations that kingdoms are based on the physiological, metabolic and structural observations, there were two kingdoms defined by Carlos Linnaeus in 1735. Those were the vegetarian animalia. In 1866, Ernest Heckle had added one more Kingdom the kingdom protest main with mainly unicellular microorganisms. Next to the kingdoms plant in animalia. In 1956, Copeland had seen that monera was a new kingdom that he wanted to form because bacteria were unicellular, black, unicellular organisms with out a nucleus which were added to the king.

Protista plant and animalia then in 1959, Whitaker had seen according to the mode of nutrition that fungi needed to be placed into a different kingdom, and therefore the kingdom fungi was added as the fifth Kingdom adding to the kingdoms monera, protista, plantain and Amalia now, the domains were based on molecular evidence in 1990 car was based on molecular analysis of rubber. So make RNA came up with domains, which was the domains bacteria, archaea and eukarya. Known As of now, this concludes our study of taxonomy.