Biodiversity And Classification Of Living Things (SBI3U1) PDF

Biodiversity and Classification of Living Things Biological Species Concept Recall:  Species – a population of organisms whose members can breed freely in nature and produce fertile offspring  Ecological, behavioural, and physical differences normally keep two different species from inter...

Biodiversity and Classification of Living Things Biological Species Concept Recall:  Species – a population of organisms whose members can breed freely in nature and produce fertile offspring  Ecological, behavioural, and physical differences normally keep two different species from interbreeding. Biodiversity  Biodiversityis the number and variety of species and ecosystems on earth.  Higher biodiversity generally leads to resiliency of the ecosystem to changes in the environment.  Keystone species are species that have a disproportionately large effect on the ecosystem in which they live.  The presence or absence of a keystone species can have a dramatic impact on an ecosystem.  E.g. pesticides applied to crops can kill insects which are responsible for pollination Genetic Diversity  Genetic diversity - The genetic variability among organisms – usually referring to individuals of the same species.  Sexual reproduction results in offspring with a unique combination of genetic information inherited from their parents.  This variation among individuals allows populations to adapt to environmental changes. Species Diversity  Species diversity - A measure of diversity that takes into account the quantity of each species present, as well as the variety of different species present.  Each species contributes to the ecosystem.  A variety of species ensures that the ecosystem is able to adapt to environmental changes. Ecosystem Diversity  Ecosystem diversity - The diverse range of habitats, organisms, and interactions that connect them.  This includes structural diversity which can create microhabitats.  Larger structural diversity can support a greater species diversity and species interactions.  E.g. food supply, protection, transportation, reproduction, hygiene, digestion Societal Impacts Loss of biodiversity can impact human populations  Threatened food supply  Eliminates sources of natural medicines  Economic impact on tourism and forestry  Disruptions to biogeochemical cycles Case Study  Honeybees have a crucial role as a pollinator.  Recent studies have shown a decline in the global population of honeybees.  Possible causes  Pesticide use  Viral infection transmitted by parasites Classification  Classify the following groups of organisms. What categories could be used? Yeast Cow Maple Tree Bee Tiger Amoeba Monkey Fern Corn Butterfly Chicken Cyanobacteria Mold Worm Hammerhead Shark Venus Fly Trap Mushroom Blue Footed Booby Lion Pigeon Whale Classification  Ifyou were to classify the organisms that cause the following diseases, what categories could be used? Strep throat Flu Anthrax HIV Mad Cow Meningitis Salmonella Cold Sores Ebola Flesh Eating West Nile E. Coli Disease Tuberculosis SARS Chlamydia Herpes Pink Eye Pneumonia Tetanus Malaria Yeast Infection Biological Classification  Classificationsystems are a source of information and a tool for communication.  Defined categories show the relationships among items.  Biological classification – The systematic grouping of organisms into biological categories based on physical and evolutionary relationships.  Organisms can be identified by observable characteristics morphology, behaviour, and geographic location Taxonomy  Taxonomy – the science of naming, identifying, and classifying all organisms. Binomial Nomenclature  Carl Linnaeus was a naturalist and botanist who is considered the father of taxonomy.  He felt that each organism should have a distinct identifying name that would help to identify it.  He grouped organisms by shared physical characteristics and developed a naming system.  Binomial nomenclature – the formal system of naming species whereby each species is assigned a genus name followed by a specific name; the two words taken together form the species name. Taxons  Linnaeus further grouped species into taxonomic levels (taxons) based on their shared characteristics. Kingdom Phylum Class Order Family Genus Spain Taxons  With binomial nomenclature, the first part of the name is the genus, and the second part of the name is the species.  The first letter of the genus is capitalized, and the whole name is italicized.  E.g. Escherichia coli, or E. coli Taxons  Each taxonomic rank consists of species that have similar features.  E.g. chordata – backbone, mammalia – warm- blooded Modern Classification  The classification system developed by Linnaeus grouped organisms according to morphology.  However, this alone was not always adequate or correct when categorizing organisms.  In 1859, Charles Darwin published The Origin of Species which outlined his theory of evolution.  This allowed biologist to develop new methods of classification that involves the evolutionary relationships between organisms based on shared ancestry.  Advances in technology have also allowed for the inclusion of molecular data into defining ancestry. Phylogeny  Phylogeny– the study of the evolutionary relatedness between, and among, species. Phylogenetic Trees  Phylogenetictree – a diagram that reflects the hypotheses of evolutionary relationships. Domains  Phylogenetic relationships have led to the development of a broader taxon known as domain.  Domain is the highest taxonomic level and there are three domains of life – Bacteria, Archaea, and Eukarya.  Bacteria and Archaea are microscopic and unicellular. They are also prokaryotes - single-celled organisms that do not contain membrane-bound organelles.  The third domain, Eukarya, consists of eukaryotes – organisms whose cells contain membrane-bound organelles.  Structure Prokaryotes Eukaryotes Membrane-bound nucleus Genetic material Free-floating, uncoated DNA with chromosomes of DNA and protein Cell division Fission or budding Mitosis Sexual Transfer of genes Meiosis recombination Tissue None, single-celled Sometimes, if multi-cellular development Respiration Not all require oxygen Almost all require oxygen Size Microscopic Mostly macroscopic Energy Enzymes in mitochondria or Free-floating enzymes production chloroplasts Flagella Simple Complex