Download
1 / 16
160 likes | 168 Views
Classification. Aim To gain an understanding of the binomial system of Classification, and the differences between the major divisions, Kingdoms and Phyla. To understand the Classification of organisms within an Ecosystem in terms of Trophic Levels. Additional Reading
E N D
Classification • Aim • To gain an understanding of the binomial system of Classification, and the differences between the major divisions, Kingdoms and Phyla. • To understand the Classification of organisms within an Ecosystem in terms of Trophic Levels. • Additional Reading Environmental Engineering, Gerard Kiely. Biology of Freshwater, Kiely, Gerard Maitland, Peter.S. Fundamentals of aquatic ecology R.S.K. Barnes and K.H. Mann. 2nd Edition
Classification of Organisms • Why Classify? • Continuity amongst Researchers • Types of Classification • Taxonomy • Scientific study of Classification and Nomenclature • Phylogeny • Ordering of species into groups having Evolutionary similarities. • Classification by Function • Individuals as part of an Ecosystem
Kingdoms of Organisms • 2 - Kingdom System • Animals • Plants • 3 - Kingdom System • Animals • Plants • Protista • 5 - Kingdom System • Monera • Protista • Fungi • Animalia • Plantae
Classification of Organisms • Animals, Plants and Microorganisms are arranged in groups which are themselves part of Larger Groups. • Hierarchical System = “Family Tree” Kingdom Individual organisms have a name from each of the Taxonomic levels. Nomenclature devised by Linnaeus Phylum Class e.g. Saccharomyces cerevisiae Order Family Genus species species
Classification of Organisms • Importance of the Major Divisions - The Eukaryotic Phyla KingdomPhylum Protista Protozoa (Rhizopoda, ciliata etc) Euglenophta (Algae) Chlorophyta (Algae) etc. Animalia Arthropoda (750,000sp, Insecta, Arachnida Crustacea, Ostracoda, Copopda) Mollusca (snails, bivalves) Aschelminths (Rotifera) Annelida (polychaete worms) etc. Chordata Class - (Amphibia, Reptilia, Aves, mammalia)
Biological Classification Conventions AnimalsBacteria Man Mosquito Typhoid Gut Bacteria Taxon Phylum Chordata Arthropoda Procaryota Procaryota Class Mammalia Insecta Selizomycetes Selizomycetes Order Primates Diptera Eubacteriales Eubacteriales Family Hominidae Culcidae Enterbacteriaceae Enterbacteriaceae Genus Homo Culex Salmonella Escherichia Species sapiens quinquefasciens typhi coli Lower ranks based on biochemical similarities. For EE, more important to be able to classify organisms at Kingdom, Phyla and possibly Class levels.
Phylogeny • Ancestor-Descendant (hypothetical) • Classical Methods • Phenotypic - morphology, behaviour, cytology. • Biochemical Methods • gram stain - Peptidoglycan • nutritional requirements, metabolism • Protein Analysis - cytochrome C, haemoglobin. • Lipid Analysis • Nucleic Acid Analysis • GC Ratios
Phylogeny • Nucleic Acid Analysis (continued) • DNA-DNA hybridisation • reflects sequence similarity • useful for species and genus level comparisons • Ribosomal RNA Sequencing 16S and 18S • very powerful technique • data can be processed mathematically • sequence highly conserved (< 97% indicates a different species) • Molecular Clock • Precise Phylogenetic Trees
Tertiary Consumers Secondary Consumers Primary Consumers Primary Producers Trophic Pyramids • Pyramids of Numbers Primary Producers are small (e.g. algae) Primary Producers are large (e.g. Tree) However, Biomass of aquatic organisms varies greatly Escherichia 0.4 x 10-12 g Bacteria Paramecium 0.4 x 10-9 g Protozoa Penicillin 1 x 10-7 g Fungus Daphnia 1 x 10-3 g Invertebrate Salmo > 100 g Fish • Is better to produce Pyramids of Biomass. Still gives pyramid shape, but with steeper slopes. • Is better still to produce Pyramids of Metabolic Contribution (Energy) Tertiary Consumers Secondary Consumers Primary Consumers Primary Producer
Metabolic Pyramid in Food Webs • Use the Productivity per unit Biomass • Smaller organisms have higher metabolic rates Bacteria 10-12 g reproduce 50 x bodyweight/d Protozoa 10-9 g reproduce 1 - 10 x bodyweight/d zooplankton 10-3 g reproduce 0.1 x bodyweight/d fish 100 g reproduce 0.01 x bodyweight/d • Productivity/Biomass Ratio • Combine P/B with Enumeration data for members within a Trophic level to give best estimate of its Metabolic Contribution (Energy). • Diversity of Organisms. • Number of species in the Community • Ecological Efficiency (5 - 15%) • Key Indicator in monitoring the ‘Condition’ of natural environments (rivers, lakes) and of STP.
