S S ONE BIOLOGY

WEEK THREE

TOPIC: CLASSIFICATION OF LIVING THINGS

Classification is the practice of placing or ordering organisms into groups based on common origin, common features, evolutionary relationship e.t.c.Definitions of Terminologies1. Taxonomy: It is the study of the general principle of classification that include nomenclature, systematics, classification and identification. 2. Systematic: It studies the kind and diversity as well as relationship that exists among organisms.

3. Classification: It is the practice of placing or ordering organisms into groups based on origin, structure, evolutionary trends e.t.c.4. Nomenclature: This is the syste of naming organisms. Binomial nomenclature is the most recent method in which two names are given to an organism. The first name is genus/generic name while the second name is species/specific name e.g man is Homo sapiens, pawpaw is carica papaya.

CONTRIBUTION OF CAROLUS LINNAEUS.He introduced binomial nomenclature.He placed all organisms into two kingdomsKingdom plantaeKingdom animaliaThis was later rejected because many unicellular organisms could not fit into either kingdoms

THE FIVE BIOLOGICAL KINGDOMS1. Kingdom monera2. Kingdom protista3. Kingdom fungi4. Kingdom plantae5. Kingdom animaliaThe only challenge with this system is that viruses could not fit into any of the five kingdoms because thers is still controversy whether they are living or non-living.

VIRUSES AS LIVING THINGSThe following features present viruses as living organisma. Possession of transmittable traits.b. Ability to reproduce when in livig cells

VIRUSES AS NON-LIVING THINGSThe following features present viruses as non-living;1. They can't respond to stimuli2. They can't reproduce outside living cell3. They assume a crystalline form when

extracted from living cells and placed in non-living medium. KINGDOM MONERAFeatures1. They are made up of simple cells2. They are prokaryotes (they do not have true nuclei)3. They are unicellular4. The chromosomes in their cells lie freely and not organised into a nuleus.5. Examples are; bacteria, viruses and blue-green algae(nostoc and oscillatoria)

MAJOR GROUPS1. Bacteria 2. Blue-green algaeBACTERIAPhylum SchizophytaClass SchizomycetesFeatures- they are unicellular and microscopic- they have different sizes- they are found everywhere- they reproduce asexually by binary fision- some are motile using flagella while others are non-motile

- harmful bacteria cause diseases in plant and animals- most are autotrophs while others are saprophyte(decomposers)- their different sizes includea. Coccus has spiral shapeb. Bacillus has rod-like shapec. Vibrios are rigid curved rodd. Spirillae are cockcrew

KINGDOM PROTISTA1. They are eukaryotes having true nulcei with nuclear membrane2. They are unicellular organisms3. Some reproduce asexually by inary fision e.g amoeba while others reproduce sexually by producing male and female sex cells.4. Most live in water, moist place and in fluids of living organism5. Many are motile using flagella, cilia or pseudopodia6. Examples are protozoa and diatoms

PHYLA OF KINGDOM PROTISTAa. Protophytab. Protozoac. EuglenophytaPHYLUM PROTOZOAFeatures1. Some are aquatic while few are parasitic2. They are animal-like protista3. They lack cellulose cell wall4. They reproduce asexually by binary fision5. Examples are amoeba, euglena, paramecium, trypanosome, plasmodium e.t.c

TYPES OF PROTOZOAThe classification of protozoa is based on the organ of locomotion1. Rhizopoda (sarcodina) move by means of pseudopodia e.g amoeba proteus2. Mastigophora (flagellate) have flagella e.g euglena, volvox, trypanosoma3. Ciliophora (ciliate) have cilia e.g paramecium4. Sporozoa: all parasitic, no external locomotory organ e.g plasmodium

PHYLUM EUGLENOPHYTA1. They are protista that show both plant-like and animal-like features2. Example is Euglena viridisANIMAL FEATURES OF EUGLENA1. Possession of flagellum for movement2. Possession of contractile vacuole for excretion3. Possession of eye spot for response to light4. Possession of pellicle for movement5. Possession of myonemes to aid movement6. Presence of gullet for passage of food and reservoir

7. In the absence of sunlight, they feed holophytically.PLANT FEATURES OF EUGLENA1. Possession of chloroplast for photosynthesis2. Possession of pyrenoids where starch is stored3. Storage of starch in form of paramylum granules4. It is able to photosynthesize in the presence of light5. Has definite shape

KINGDOM FUNGIFeatures1. They are multicellular organisms2. They have cell wall, not made up of cellulose but chitin3. Fungi lack true roots, stems or leaves4. They are either parasites or saprophytes5. They lack chlorophyll6. They store excess food in form of glycogen7. They reproduce sexually by cnjugation and asexually by forming spores8. They have root-like structures known as

rhizoids and stem-like structure called stolon9. They are made up of many tubes of cytoplasm called hyphae which forms a mass of mycellium10. Fungi include Rhizopus/bread mould , mildews, yeasts, mucor, mushroom, toadstool e.t.c.ECONOMIC IMPORTANCE OF FUNGI1. Yeast is used in bakeries as a rising agent2. They spoil food3. They are decomposers and so they improve soil fertility4. They are used in the production of antibiotics

e.g penicillin is produced from penicillium5. They are used industries that employ fermentation processes like wine-making and beer-brewing6. Edible mushrooms are good source of nutrients.7. They can cause diseases in both plants and animaks e.g mildew in plant and ringworm in animals

ASSIGNMENTDraw and label the following1. A virus2. A bacterium cell3. Amoeba proteus4. Euglena viridis5. Rhizopus nigricans