Taxonomy - Bosna Semacdn.bosnasema.ba/unasanacollegeeduba/download_area/e283159…  · Web viewPeople love classified things, to put them into one group and they classified them

1. Taxonomy

People love classified things, to put them into one group and they classified them into what they thought may sense. The scientific study of the diversity of organisms and their evolutionary relationship is called systematic. An important aspect of systematic is taxonomy, the science of naming describing and classifying organisms. The term classification means ordering organisms into group based on their similarities and relationship. On the many classification that systems were developed the one designed by Carlos Linnaeus has survived with some modification to the present day. Use of analogues organs in classification was replaced with use of homologues organs. Scientist thought let's group them into some categories and they end up with system based on evolutionary relationship.

Analogues organs are organs generally similar in shape and function. Ex. wings in butterflies or birds provide flight. But these organs are embryological different. Therefore the butterfly and birds are not relegated.

Homologues organs are organs that share the same origin and similar embryological stages. Function homologues organs may be same or different. Homologues organs are the basis of mordent classification.

The founder of mordent systematic and „Father of Taxonomy” was Carl von Linnaeus. Linnaeus creates three of life. He simplified scientific classification, developing a binomial system of nomenclature in which each species is assigned a unique two part name. The first is genus name, second is specific name. Both are written italic and in Latin. Ex. people bellow species Homo sapiens, Homo is name of genus and sapiens is name of species (Figure 1-1). He classified groups as either plants or animals. Organisms which eat, moved, breath Linnaeus put into animal group. This is contrasted with organisms which have no apparent eating, moving, and breathing. Into this group Linnaeus put organisms and classified as plants. This classification scheme from Linnaeus up and persist until 1930. From 1930 was clear that system is artificial. Scientist grouped a species similar in some characteristics in genus, and they thought maybe we can classify similar genera into orders, orders into class and similar class form phylum. Similar phyla form kingdom. So, he made seven levels of organization, Kingdom, Phylum, Class, Order, Family, Genus, and Species.Based on fundamental molecular differences systematic use level of classification above the kingdom, called a domain. They classified organisms into three domains or super kingdoms: Archie, Eubacteria (also called bacteria) and Eucarya (have nucleus). The traditional classification system, kingdom system we use five kingdom approaches: Protista, Protista, Fungi, Plantae and Animalia (Fig 1-2).

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Figure 1-1 Hierarchy of classification living thing using species Homo sapiens

Figure 1-2 Traditional classification system

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2. Kingdom Monera

Bacteria are prokaryotes they consist only from nucleic acid and protein. Some biologist assignee them into their own kingdom: Archaebacteria and Eubacteria. Other including microbiologist prefer assign to two domains: Archaea and Eubacteria. Bacteria cause all set of negative things, tuberculosis, and bacterial infection. But there some good things some produce yogurt, help to digest food. They have a big bundle of DNA which is not surrounded by nuclear membrane. The region in which DNA is located in cytoplasm is called nucleoid. They also have ribosome which produce proteins and proteins produce flagella. Flagella are something like leg for bacteria. They move with flagella. They can have one or several flagella. Outside of cell membrane is cell wall composed of peptidoglican. On the surface cell membrane are stacked all these structures called pile. They are something like sex organ of bacteria (Figure 2-1). Bacteria can do both and cellular respiration and photosynthesis (blue- green algae).

Figure 2-1 Bacterium structure

How these organisms reproduce, how one bacterium produce more bacteria?

Binary fusion. It is type of asexual reproduction. The DNA joust replicate itself and cytoplasm splits on two bacteria. They reproduce so quickly every 20 min one generation. (Figure 2-2).

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Figure 2-2 Simple processes of binary fusion in bacteria

The process in which two bacteria exchange genetic material is called conjugation. Two bacteria get close each other and one of their piluses (little tubes) can connect one bacterium with other. Cytoplasm of donor bacteria has extra plasmid and he able her to do what other not. This plasmid replicate itself and passes thought pills into cytoplasm of bacteria where is missing (recipient bacteria). The transport stuff via this pilli is called conjugation (Figure 2-3).

Figure 2-3 Schematic drawing of bacterial conjugation

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How bacteria are classified?

According to shape: a) Rod shape bacteria –Bacillus (they look like finger)b) Spherical bacteria – Coccus (they look like circle). Some of them like to live

alone they are called monococcus. If they like to live in pair they are called diplococcus, or they prefer like to live in group, consisting of long chain (streptococcus) or cluster of them (staphylococcus).

c) Spiral or curved bacteria – spirillum (they have flagella on both sides).d) Comma shaped bacteria- Vibrium (they have one end curved while the others end

has flagella) (Figure 2-4).

According to environment in which they are found:a) Aerobic bacteria- these need oxygen in their environment, respiration is aerobic.

They live on the ground or on the near the surfaces of bodies of waters.b) Anaerobic bacteria- These live without oxygen. They are founded deeper layers of

soils and at the bottom of lakes and seas.c) Facultative anaerobic bacteria- live with or without oxygen, and can be food in all

layers of soil and water.

According to ability to absorb gram stain. If they absorb gram stain and go in purple color we called them gram positive bacteria, if they don’t absorb blue-purple color when dyed with gram stain they go in red stain we called them gram negative bacteria. Archaebacteria are unicellular microscopic, cell walls do not have peptidoglycan. They have similar transcription and translation process to eukaryote, but they are differ biochemical from eukaryote (Figure 2-5).

Figure 2-4 Bacterial shape and size

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Figure 2-5 The gram staining

3. Kingdom Protist

If you look at a drop of pond water under a microscope, all the "little creatures" you see swimming around are protests. All protist have a nucleus and are therefore eukaryotic. Protists are plant-like, animal-like or fungus-like.Plant-like protists are autotrophs – they contain chloroplasts and make their own food.Animal-like and fungus-like protists and are heterotrophs.

Protozoans are animal-like protists (heterotrophs) grouped according to how they move. The word protozoa means “little animal." They are so named because many species behave like tiny animals—specifically, they hunt and gather other microbes as food. All protozoa digest their food in stomach-like compartments called vacuolesThe first group is the phylum Rhizopoda. These are amoebae <ah-me-bee. Amoebae ooze along by means of pseudopodia (false feet) engulfing food as they go. Amoebae live in water or moist places. They have a cell membrane but no cell wall (Figure 3-1).

Figure 3-1 Amoeba proteus

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The second group is the Flagellates, of the phylum Zoomastigina. Flagellates are generally the smallest of the protozoa and have one or several long, whip-like projections called flagella poking out of their cells. Flagellates use their flagella to move(Figure 3-2).

Figure 3-2 Giardia

The third group of protozoan is the ciliates from the phylum Ciliophora. These are generally the largest protozoa. They are covered with hair-like projections called cilia and they eat the other two types of protozoa as well as bacteria. Ciliates are found in every aquatic habitat (Figure 3-3).

Figure 3-3 Paramecium sp.

The last of the Protozoans come from the phylum, Sporozoa. These are parasitic and no motile.

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Plant-like protists are algae. Algae are eukaryotic autotrophs. They, along with other eukaryotic autotrophs, form the foundation of Earth’s food chains. They produce much of Earth’s oxygen.There are three unicellular phyla of algae:

1. Phylum Euglenophyta2. Phylum Bacillariophyta3. Phylum Dinoflagellata4. Phylum Chlorophyta (green algae)5. Phylum Rodophyta (red algae)6. Phylum Phaeophyta (brown algae)

Members of first phylum of algae, Euglenophyta, are both plant-like and animal-like. They are unicellular. Euglena is autotrophs since they make food from sunlight and Heterotrophs since they ingest food from surrounding water.The second unicellular algae, Bacillariophyta, are photosynthetic autotrophs. They have shells of silica. They make up a large portion of the world’s phytoplankton which is Earth’s largest provider of oxygen.The third unicellular algae, Dinoflagellata, are a major component of marine phytoplankton. These algae have at least two flagella set at right angles to each other and thick cell walls made of cellulose plates. Blooms of dinoflagellates cause “Red Tide.”They are pigmentated (chlorophyll a and b, carotenoids).Rhodophyta are red seaweeds. Except for a few unicellular examples, they are multicelular. Rodophyte are found in warm or cold marine environments along coast lines in deeper water. They absorb green, violet, and blue light waves. These light waves are able to penetrate below 100 meters. The multicellular Phylum Phaeophyta is made up of the brown algae. They are found in cool saltwater along rocky coasts. Giant Kelp is the largest and most complex brown algae. They have hold fasts and air bladders.A Volvox is a hollow boll composed of hundreds of flagellated cells in a single layer.The last of the plant like protista is phylum Chlorophyta. These organisms are unicellular or colonial species, as well as multicellular species that are not organized into tissue. Most green algae are found in fresh water habitats. Chlamydomonas are actually unicellular and flagellated.

Fungus-like protist, Myxomycota and Oomycota are decomposers. Phylum Myxomycota are made up of plasmodia slime molds. They are multinuclear with amoeboid movement.Phylum Oomycota is made up of water molds and downy molds. Cell wall may be chitinous (like in fungi) or cellulous (like in plants).

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