Biological Classification PDF

Biological Classification © 2022, Aakash BYJU'S. All rights reserved. Key Takeaways Aristotle Classification 1 2 Five Kingdom Classification 3 4 Kingdom Monera Characteristics Classification of bacteria © 2022, Aakash BYJU'S. All rights reserved. Two Kingdom Classification Six Kingdom Classification...

Biological Classification © 2022, Aakash BYJU'S. All rights reserved. Key Takeaways Aristotle Classification 1 2 Five Kingdom Classification 3 4 Kingdom Monera Characteristics Classification of bacteria © 2022, Aakash BYJU'S. All rights reserved. Two Kingdom Classification Six Kingdom Classification 5 6 Kingdom Protista Kingdom Fungi Reproduction Classification Kingdom Animalia Viroids Lichen 8 9 10 11 Viruses 12 Viral infections 13 Prions 14 Summary © 2022, Aakash BYJU'S. All rights reserved. Kingdom Plantae Aristotle Classification Aristotle Father of biology Earliest scientific classification, based on simple morphological characters Classified living things as, plants and animals Merit: First novel attempt of classification of living organisms Demerit: No evolutionary relationships consideration Soft Stem (Herbs) Plants One Woody Stem (Trees) Several Woody Stems (Shrubs) Enaima (with RBC) Animals © 2022, Aakash BYJU'S. All rights reserved. On basis of RBC Anaima (without RBC) Two Kingdom Classification Carolus Linnaeus Father of systematic botany Gave two kingdom classification Wrote Species Plantarum and Systema Naturae Main basis of classification - Presence or absence of cell wall Demerits: Unable to differentiate between the following; o Unicellular and Multicellular o Prokaryotic and Eukaryotic o Photosynthesis and Non photosynthetic organisms Two kingdom classification (1758) Plantae © 2022, Aakash BYJU'S. All rights reserved. Animalia Five Kingdom Classification Robert H. Whittaker Proposed five kingdom classification in 1969 Established Kingdom Fungi Based on : Cell structure, Body organisation, Mode of nutrition, Reproduction and Phylogenetic relationship Limitations Some unicellular algae (Chlamydomonas) are kept in Kingdom Protista, away from remaining algae placed in Kingdom Plantae. Chlorella and Chlamydomonas (autotrophic) placed with Paramecium and Amoeba (heterotrophic) in Kingdom Protista No place for lichens Five-Kingdom Classification Monera © 2022, Aakash BYJU'S. All rights reserved. Protista Fungi Plantae Animalia Five Kingdom Classification Organisms Cell type Prokaryotes Body organisation Unicellular Unicellular Monera Protista Eukaryotes Maximum mode of nutrition Second maximum mode of nutrition With cell wall Cell wall No photosynthesis Mode of nutrition Fungi Chitinous cell wall Saprophytic or parasitic mode of nutrition © 2022, Aakash BYJU'S. All rights reserved. Multicellular No cell wall Photosynthesis Plantae Cellulosic cell wall Autotrophic mode of nutrition Animalia No cell wall Holozoic or parasitic mode of nutrition Six Kingdom Classification Carl Woese Proposed six kingdom or three domain classification in 1990. The classification is based on the sequence of 16S rRNA which is supposed to be conserved and present across all kingdoms. Six Kingdom Classification 3 Domains Archaea Bacteria 6 Kingdoms Archaebacteria Eubacteria © 2022, Aakash BYJU'S. All rights reserved. Eucarya Protista Plantae Fungi Animalia Kingdom Monera Characteristics Prokaryotes (includes all bacteria) Ubiquitous Double-stranded circular DNA Membrane-bound cell organelles absent Rigid cell wall 70s ribosomes Maybe motile (flagella) or non-motile Nutrition - Heterotrophic (saprophytic/parasitic) or autotrophic Virus Animal cell Bacterium Nucleus Cell size comparison Cytoplasm Nucleoid Plasma membrane Capusle (DNA) Prokaryotic cell Flagellum Ribosomes © 2022, Aakash BYJU'S. All rights reserved. Cell wall Pilus Kingdom Monera Classification of bacteria Based on their shape: Cocci Bacilli Spore © 2022, Aakash BYJU'S. All rights reserved. Spirilla Flagellum Vibrio Kingdom Monera Reproduction in bacteria Asexual Sexual Binary fission Sporulation The process in which the parent cell divides into two independent daughter cells. Conjugation The process in which the parent cell produces spore/spores, each of which can develop into an independent organism. Spore Cell Endospore Exospore Present within the cell Present outside the cell Spore formation (unfavourable conditions) © 2022, Aakash BYJU'S. All rights reserved. It refers to the process by which one bacterium transfers its genetic material to another bacterium through direct contact. Kingdom Monera Archaebacteria Eubacteria Halophiles Cyanobacteria Thermoacidophiles Heterotrophic bacteria Methanogens Actinomycetes Mycoplasma © 2022, Aakash BYJU'S. All rights reserved. Kingdom Monera Archaebacteria They are the most primitive group that occurs in extreme habitats. Their cell wall is made of pseudopeptidoglycan (pseudomurein). They are classified into three groups: Halophiles They are found in extremely saline environments. They have been observed in The Great Salt Lake, U.S.A. E.g. : Halobacterium © 2022, Aakash BYJU'S. All rights reserved. Thermoacidophiles They are found in environments having high temperature and low pH. They have been observed in Yellowstone Acid pool, U.S. E.g. : Sulfolobus Methanogens They are found in the gut of ruminants. They are responsible for the production of methane from dung. E.g.: Methanobacterium Kingdom Monera Eubacteria They are also known as ‘true bacteria’ and their cell wall is made of peptidoglycan. They can be of the following types depending on the mode of nutrition: Cyanobacteria Chemosynthetic autotrophs Heterotrophic bacteria Actinomycetes Mycoplasma Also known as blue-green algae. Photosynthetic autotrophs that contain chlorophyll a, phycocyanin and phycoerythrin Show gliding and oscillatory movements and are covered by a gelatinous sheath Found in freshwater, marine or terrestrial regions E.g. : Anabaena, Nostoc ( both are heterocysts as well) Three types: Spirulina (Unicellular) © 2022, Aakash BYJU'S. All rights reserved. Microcystis (Colonial) Nostoc (Filamentous) Kingdom Monera Eubacteria Chemosynthetic autotrophs These bacteria oxidise inorganic substances such as nitrates, nitrites, and ammonia. Energy thus released is used for ATP production. © 2022, Aakash BYJU'S. All rights reserved. Heterotrophic bacteria Most abundant in nature Most of them are saprophytes Useful in: o Curd formation from milk o Nitrogen fixation in the roots of leguminous plants o Production of antibiotics Some are pathogenic Cause diseases in plants, animals, and humans (cholera, typhoid, etc.) Kingdom Monera Eubacteria Actinomycetes Mycelial bacteria that help decompose organic materials (chitin) Produce antibiotics Commonly found in soil and aquatic regions (both freshwater and marine) E.g. : Streptomyces © 2022, Aakash BYJU'S. All rights reserved. Mycoplasma Smallest living cells Also called PPLO (Pleuro Pneumonia Like Organisms) Lack cell wall and are non-motile Exhibit pleomorphism and can survive without oxygen Pathogenic to plants and animals Kingdom Protista They are single-celled/colonial eukaryotes that evolved from prokaryotes (endosymbiosis). They are primarily aquatic and use cilia and flagella for locomotion. Their reproduction is sexual and asexual. Kingdom Protista Chrysophyta Diatoms Plant like Fungi like Pyrrophyta Euglenophyta Desmids © 2022, Aakash BYJU'S. All rights reserved. Animal like Kingdom Protista Chrysophyta Live in freshwater and marine environments Most are photosynthetic Float passively in water currents (plankton) They can be o diatoms o desmids Diatoms Desmids © 2022, Aakash BYJU'S. All rights reserved. Chief producers of the ocean Unicellular/colonial, and cell wall contains silica Mostly non-motile or show gliding movement Dead diatoms form diatomaceous earth (fossilised geological deposit of nearly pure diatoms frustules) Used in polishing, filtration of oils and syrups, toothpaste, metal polishes and facial scrubs Also known as golden algae Unicellular and microscopic Have a golden hue due to pigment fucoxanthin and oil droplets Food reserve is oil droplets Kingdom Protista Pyrrophyta Euglenophyta It consists of category of organisms called dinoflagellates. They consist of euglenoids among others. They are microscopic, unicellular and biflagellate organisms. Euglenoids are unicellular, biflagellate and microscopic, freshwater organisms. Their cell walls have stiff cellulose plates. They have pellicle instead of a cell wall. Mode of nutrition: They are mostly marine and photosynthetic. They are yellow, green, brown, blue or red in appearance due to varying pigments. Toxins released are harmful to fishes. © 2022, Aakash BYJU'S. All rights reserved. In the presence of sunlight, it carries out photosynthesis. In the absence of sunlight, it has heterotrophic (holozoic) mode of nutrition. Hence, it is a link between plants and animals. Kingdom Protista Fungi-like protists/ Slime moulds Cellular slime moulds They are amoeba-like cells with no cell wall. They move and capture by pseudopodia. They remain grouped but as unfused cells. © 2022, Aakash BYJU'S. All rights reserved. Acellular slime moulds It forms plasmodium under suitable conditions. o Plasmodium is the type of body which is made up of wall less multinucleated protoplasmic mass. They do not have a cell wall and are multinucleated. They grow and spread over several feet and form spores during unfavourable conditions. Kingdom Protista Animal like protozoans Unicellular and mostly heterotrophs. Mode of nutrition is holozoic or parasitic. They possess structures for movement. They are of 4 types: Amoeboid Live in freshwater, seawater or moist soil and show amoeboid movement (pseudopodia) Marine forms have silica shells on their surface Some may be parasites E.g. : Amoeba, Entamoeba histolytica Flagellated © 2022, Aakash BYJU'S. All rights reserved. Free-living or parasitic Flagellated Marine and freshwater organisms May cause diseases such as sleeping sickness Example: Trypanosoma brucei Ciliated Aquatic Have a cavity that open to outside of cell surface Cilia help in feeding E.g. : Paramecium, Vorticella Sporozoans Parasites of animals Cause diseases Have an infectious spore-like stage May have more than one host E.g. : Plasmodium (malarial parasite) Kingdom Fungi Characteristics Kingdom Fungi, also known as Mycota, was introduced to the Five Kingdom Classification by R.H. Whittaker. Fungi are eukaryotic decomposers. The study of fungi is known as mycology. Except for yeast, all fungi are multicellular organisms. Their cell wall is made up of chitin and polysaccharides. Food is stored in the cell in the form of glycogen and oil bodies. © 2022, Aakash BYJU'S. All rights reserved. Habitat Fungi are widely distributed; they prefer warm and humid environments. Predominantly terrestrial, but are found in water, air and on animals and plants. Dikaryophase Some fungi exist in a special condition called dikaryon where each cell has 2 nuclei (n+n). Kingdom Fungi Structure of fungi Fungi have a filamentous body known as hyphae. The hyphae form a network known as the mycelium. The mycelium can be of two types: Septate - Hyphae have cross-walls or septae Aseptate - Hyphae contain a multinucleate continuous cytoplasm Septum Hyphae Septate hyphae © 2022, Aakash BYJU'S. All rights reserved. Nucleus Coenocytic hyphae Kingdom Fungi Mode of nutrition Fungi are achlorophyllous - they lack chlorophyll; hence they are heterotrophic. Parasitic Saprophytic Saprophytic fungi grow on dead plant and animal matter. They break down and recycle the soluble organic matter that they absorb from the dead substrates. © 2022, Aakash BYJU'S. All rights reserved. These fungi grow on a living host and absorb nourishment from the host. In this process, they may harm and sometimes even kill the host. Symbiotic Fungi form a symbiotic association with organisms to derive nourishment. Example 1: Lichen Association of algae with fungi. Example 2: Mycorrhiza Association of fungi with roots of higher plants. Kingdom Fungi Reproduction 3 modes of reproduction: Vegetative Fragmentation Sexual (Involves 4 types of spores) Oospores Asexual (Involves 3 types of spores) Sporangiospores Zygospores Fission Conidiospores Ascospores Budding © 2022, Aakash BYJU'S. All rights reserved. Basidiospores Zoospores Kingdom Fungi Sexual reproduction During sexual reproduction, three types of gametic fusion are observed: o Isogamy: Fusion of gametes of similar size o Anisogamy: Fusion of one big and one small gamete o Oogamy: Fusion of a large, non-motile female gamete and a small, motile male gamete. © 2022, Aakash BYJU'S. All rights reserved. Mycelium (n) Plasmogamy: Cells from two different mycelia fuse to form a dikaryotic cell Sexual reproduction Spores Heterokaryotic stage Karyogamy: Nuclei fuse to form a diploid zygote Germination: Multicellular mycelium is formed Zygote Meiosis: Haploid spores are formed Kingdom Fungi Classification of fungi Fungi Aseptate mycelium Phycomycetes Septate mycelium Deuteromycetes Basidiomycetes Ascomycetes © 2022, Aakash BYJU'S. All rights reserved. Classification of Fungi Phycomycetes They have aseptate or coenocytic mycelium. They can survive: o In aquatic o In moist decaying wood as obligate parasites. Reproduction o Asexual reproduction by sporangiospores o Sexual reproduction by oospores/zygospores © 2022, Aakash BYJU'S. All rights reserved. Aseptate mycelium Phycomycetes Oomycetes Zygomycetes Classification of Fungi Phycomycetes Type of gametic fusion Process of Sexual reproduction Isogamous Or Anisogamous Oospore Fertilisation Examples Haploid Spores Meiosis Phytophthora infestans Albugo candida © 2022, Aakash BYJU'S. All rights reserved. New Organism Germination Isogamous or Anisogamous Oospore Fertilisation Haploid Spores Meiosis Rhizopus (bread mould) Mucor New Organism Germination Classification of Fungi Ascomycetes 01 Characteristics 02 03 Reproduction Sexual Reproduction © 2022, Aakash BYJU'S. All rights reserved. Commonly called ‘sac fungi’ Saprophytic, decomposers, parasitic, or coprophilous (growing on dung) Rarely unicellular (yeast) mostly multicellular (Penicillium) Septate, branched mycelia Vegetative by budding Asexual by conidiophores Sexual by ascospores produced in sac like asci Ascocarp (fruiting body) Ascus 8 Ascospores Classification of Fungi Ascomycetes Economically important ascomycetes Saccharomyces cerevisiae Penicillium notatum Morels Claviceps purpurea Truffle Neurospora Aspergillus, Claviceps and Neurospora are used extensively in biochemical and genetic work. Morels and truffles are edible and used in delicacies. Penicillium and Saccharomyces can be saprophytic, decomposers, parasitic, or coprophilous. © 2022, Aakash BYJU'S. All rights reserved. Aspergillus Classification of Fungi Basidiomycetes Commonly called ‘club fungi’ Grow in soil, on logs and tree stumps Parasitic (rusts and smuts) 01 Characteristics 02 Reproduction Vegetative by fragmentation Asexual spores are generally not found Sex organs absent Sexual reproduction is by somatogamy Fusion of somatic or vegetative cells result in formation of basidium 03 Sexual Reproduction Basidiocarp (fruiting body) © 2022, Aakash BYJU'S. All rights reserved. Basidia Basidiospores Classification of Fungi Ascomycetes Basidiomycetes Mushroom © 2022, Aakash BYJU'S. All rights reserved. Bracket fungi Puffballs Classification of Fungi Some important members of Basidiomycetes Cause smuts. Ears of cereals turn into black powder. Seen in wheat, corn and Sorghum Cause rust disease Parasitic Completes life cycle in two hosts - wheat and barberry Forms four types of spores: o Infecting wheat: Urediniospores, Teliospores, Basidiospores o Infecting barberry: Aeciospore Corn smut Puccinia © 2022, Aakash BYJU'S. All rights reserved. Classification of Fungi Deuteromycetes 01 02 Also called as ‘fungi imperfecti’. Mycelia are septate and branched. Saprophytic or parasitic mode of nutrition. Help in mineral cycling. Vegetative reproduction. Asexual reproduction by conidia. Sexual reproduction not reported. Characteristics Reproduction Examples Alternaria © 2022, Aakash BYJU'S. All rights reserved. Trichoderma Colletotrichum Kingdom Plantae Characteristics of Kingdom Plantae: Autotrophic Eukaryotic Cell wall made up of cellulose Starch as reserve food material Some show partial heterotrophic nutrition: o Insectivorous (Venus Fly trap). o Parasitic (Cuscuta). © 2022, Aakash BYJU'S. All rights reserved. Cuscuta Venus fly trap Kingdom Plantae Life cycle shows alternation of generation o Diploid sporophytic phase o Haploid gametophytic phase Algae Bryophytes Plants Pteridophytes Gymnosperms Angiosperms © 2022, Aakash BYJU'S. All rights reserved. Kingdom Animalia General characteristics Kingdom Animalia consists of several phyla of eukaryotic organisms. The cells lack a cell wall. They show tissue/organ/organ system level of organisation. A definite growth pattern can be seen. Complex sensory and neuromotor mechanisms can be seen in higher organisms. Most members of the kingdom show locomotion. © 2022, Aakash BYJU'S. All rights reserved. Mode of nutrition Heterotrophic o Holozoic (by ingestion) The food consumed is stored in the form of glycogen or fat. Reproduction Sexual Asexual Both sexual and asexual Viruses Discovery Dmitri Ivanovsky Coined the term ‘virus’ (venom) Worked on Tobacco Mosaic Virus Found that virus was smaller than bacteria as they passed through bacteria proof filters Demonstrated that extract from infected tobacco plants caused disease in healthy plants Called the extract ‘Contagium vivum fluidum’ (infectious living fluid) M.W. Beijerinck W.M. Stanley © 2022, Aakash BYJU'S. All rights reserved. Crystallised Tobacco Mosaic Virus (TMV) Crystals mostly consisted of proteins Viruses Structure They contain infectious genetic material (either DNA or RNA, never both) The infectious material is covered by a protein coat called capsid. Capsid is made of subunits called capsomeres. o Capsomeres are arranged in helical or polyhedral geometric forms. Nucleic acid Capsid Capsomere © 2022, Aakash BYJU'S. All rights reserved. Viruses Characteristics They are obligate intracellular parasites and cause diseases in the host. Viruses are neither living nor non-living. Living properties Non-living properties Contains genetic material (DNA or RNA) Acellular Surrounded by protein coat Obligate parasites Undergoes mutation Inert crystalline structure Reproduces in living host Lacks enzyme system © 2022, Aakash BYJU'S. All rights reserved. Viral Infections Tobacco mosaic disease in plants Caused by the Tobacco Mosaic Virus. Symptoms in plants include: o Leaf curling o Leaf rolling o Mosaic formation o Yellowing and vein clearing o Dwarfing Viral infections in humans AIDS Influenza Hepatitis Herpes Polio Small pox © 2022, Aakash BYJU'S. All rights reserved. Viroids Discovered by T.O Diener in 1971 Consists of free RNA of low molecular weight Cause disease like the potato spindle tuber disease Viroids Virus Lacks protein coat Has protein coat Genetic material is RNA Genetic material can be DNA or RNA Smaller Larger Viroids Structure Virus structure Spike Nucleic acid © 2022, Aakash BYJU'S. All rights reserved. Envelope Prions Prions are abnormally folded proteins Similar in size to virus Cause neurodegenerative diseases Highly infectious (untreatable and fatal) Scrapie infected sheep © 2022, Aakash BYJU'S. All rights reserved. Creutzfeldt Jacob Disease (CJD) in humans: Degenerative brain disorder Bovine Spongiform Encephalopathy (BSE) or Mad Cow Disease Lichen Lichen is the symbiotic association between algae (phycobiont) or Cyanobacteria (cyanobiont) and fungi (mycobiont). MYCOBIONT (fungus) HETEROTROPHIC Provides nutrition CYANOBIONT (Cyanobacteria) or PHYCOBIONT (green algae) AUTOTROPHIC LICHEN (symbiosis) Absorbs water, minerals and provides shelter Lichen are early colonizers of barren land It is also used in making Litmus indicators. They are also bioindicators of air pollution (sensitive to SO2). © 2022, Aakash BYJU'S. All rights reserved. Summary History of classification Aristotle Classification Plants Two Kingdom Classification Plantae Five Kingdom Classification Monera Protista Animals Animalia Fungi Six Kingdom Classification Archaebacteria Eubacteria Protista Plantae Plantae Fungi Animalia Animalia © 2022, Aakash BYJU'S. All rights reserved. Summary Kingdom Monera Characteristics of Kingdom Monera Double-stranded circular DNA Membrane-bound cell organelles absent Rigid cell wall 70S ribosomes Chromatophores (containing pigment) Maybe motile (flagella) or non-motile Nutrition - Heterotrophic (saprophytic/parasitic) or Autotrophic © 2022, Aakash BYJU'S. All rights reserved. Classification of bacteria (based on shape) Cocci Bacilli Spore Spirilla Flagellum Vibrio Summary Kingdom Protista They are single-celled/colonial eukaryotes that evolved from prokaryotes (endosymbiosis). They are primarily aquatic and use cilia and flagella for locomotion. Their reproduction is sexual and asexual. Kingdom Protista Chrysophyta Diatoms Plant like Fungi like Pyrrophyta Euglenophyta Desmids © 2022, Aakash BYJU'S. All rights reserved. Animal like Summary Kingdom Fungi Modes of nutrition Fungi are achlorophyllous - they lack chlorophyll; hence they are heterotrophic. Saprophytic Parasitic Symbiotic Modes of reproduction 3 modes of reproduction: Vegetative © 2022, Aakash BYJU'S. All rights reserved. Sexual (Involves 4 types of spores) Asexual (Involves 3 types of spores) Summary Kingdom Fungi Classification of fungi Fungi Aseptate mycelium Septate mycelium Deuteromycetes Phycomycetes Ascomycetes Basidiomycetes © 2022, Aakash BYJU'S. All rights reserved. Mushroom Bracket fungi Puffballs Summary Viruses Scientists with major contribution in discovery of viruses. M.W. Beijerinck Dmitri Ivanovsky W.M. Stanley Structure Viruses contain either DNA or RNA, never both. The infectious material is covered by a protein coat called capsid.​ © 2022, Aakash BYJU'S. All rights reserved.