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 Terminologies 1. 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 kingdoms Kingdom plantae Kingdom animalia This was later rejected because many unicellular organisms could not fit into either kingdoms

THE FIVE BIOLOGICAL KINGDOMS 1. Kingdom monera 2. Kingdom protista 3. Kingdom fungi 4. Kingdom plantae 5. Kingdom animalia The 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 THINGS The following features present viruses as living organism a. Possession of transmittable traits. b. Ability to reproduce when in livig cells VIRUSES AS NON-LIVING THINGS The following features present viruses as non- living; 1. They can't respond to stimuli 2. They can't reproduce outside living cell 3. They assume a crystalline form when

extracted from living cells and placed in non- living medium. KINGDOM MONERA Features 1. They are made up of simple cells 2. They are prokaryotes (they do not have true nuclei) 3. They are unicellular 4. 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 GROUPS 1. Bacteria 2. Blue-green algae BACTERIA Phylum Schizophyta Class Schizomycetes Features - 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 include a. Coccus has spiral shape b. Bacillus has rod-like shape c. Vibrios are rigid curved rod d. Spirillae are cockcrew

KINGDOM PROTISTA 1. They are eukaryotes having true nulcei with nuclear membrane 2. They are unicellular organisms 3. 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 organism 5. Many are motile using flagella, cilia or pseudopodia 6. Examples are protozoa and diatoms

PHYLA OF KINGDOM PROTISTA a. Protophyta b. Protozoa c. Euglenophyta PHYLUM PROTOZOA Features 1. Some are aquatic while few are parasitic 2. They are animal-like protista 3. They lack cellulose cell wall 4. They reproduce asexually by binary fision 5. Examples are amoeba, euglena, paramecium, trypanosome, plasmodium e.t.c

TYPES OF PROTOZOA The classification of protozoa is based on the organ of locomotion 1. Rhizopoda (sarcodina) move by means of pseudopodia e.g amoeba proteus 2. Mastigophora (flagellate) have flagella e.g euglena, volvox, trypanosoma 3. Ciliophora (ciliate) have cilia e.g paramecium 4. Sporozoa: all parasitic, no external locomotory organ e.g plasmodium

PHYLUM EUGLENOPHYTA 1. They are protista that show both plant-like and animal-like features 2. Example is Euglena viridis ANIMAL FEATURES OF EUGLENA 1. Possession of flagellum for movement 2. Possession of contractile vacuole for excretion 3. Possession of eye spot for response to light 4. Possession of pellicle for movement 5. Possession of myonemes to aid movement 6. Presence of gullet for passage of food and reservoir

7. In the absence of sunlight, they feed holophytically. PLANT FEATURES OF EUGLENA 1. Possession of chloroplast for photosynthesis 2. Possession of pyrenoids where starch is stored 3. Storage of starch in form of paramylum granules 4. It is able to photosynthesize in the presence of light 5. Has definite shape

KINGDOM FUNGI Features 1. They are multicellular organisms 2. They have cell wall, not made up of cellulose but chitin 3. Fungi lack true roots, stems or leaves 4. They are either parasites or saprophytes 5. They lack chlorophyll 6. They store excess food in form of glycogen 7. They reproduce sexually by cnjugation and asexually by forming spores 8. They have root-like structures known as

rhizoids and stem-like structure called stolon 9. They are made up of many tubes of cytoplasm called hyphae which forms a mass of mycellium 10. Fungi include Rhizopus/bread mould, mildews, yeasts, mucor, mushroom, toadstool e.t.c. ECONOMIC IMPORTANCE OF FUNGI 1. Yeast is used in bakeries as a rising agent 2. They spoil food 3. They are decomposers and so they improve soil fertility 4. They are used in the production of antibiotics

e.g penicillin is produced from penicillium 5. They are used industries that employ fermentation processes like wine-making and beer-brewing 6. 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

ASSIGNMENT Draw and label the following 1. A virus 2. A bacterium cell 3. Amoeba proteus 4. Euglena viridis 5. Rhizopus nigricans