Traits & Characteristics of Life

1. Traits & Characteristics of Life • Taxonomy is the branch of biology that groups and names organism based on studies of their different characteristics. • Classification is the grouping of objects or information based on similarities.

2. Classification • As far back as Aristotle 2000 years ago, people have attempted to organize living organisms into separate and distinct categories using visible characteristics, most notably the structure of the organism’s body. • However, no uniform system of classification existed until CarolusLinneaus developed a simple system based on form and structure.

3. Carolus Linnaeus • Swedish naturalist • Developed a simple method of grouping organisms that is still used today. • Based on the form and structural similarities of organisms.

4. Scientific Names- Binomial Nomenclature • Two-word naming system • First word-Genus (plural genera) consists of a group of similar species • Second word-species name, specific characteristics • Latin b/c it’s a “dead” language • Should be italicized in print and underlined when handwritten. • 1st letter of genus name must be capitalized, species name is never capitalized, always lower case

5. Taxonomic Rankings • Organisms are ranked in taxa that range from having very broad characteristics to very specific ones. • The broader the taxa, the more general its characteristics • Order • Family • Genus • species • Domain • Kingdom • Phylum • Class

6. Six Kingdoms of Organisms • Archaebacteria • Eubacteria • Protists • Fungi • Plants • Animals

7. ALL Prokaryotes • Organisms with cells that lack distinct membrane-bound nuclei • Have cell walls • Are microscopic • Unicellular • Either heterotrophic or autotrophic

8. Archaebacteria • Prokaryotes that live in very harsh, anaerobic environments, get energy for growth from chemicals in the environment. • Biochemically different from other prokaryotes. Cell walls made without peptidoclycan • Genes have similar structure to those in eukaryotes • Methanogens are organisms that produce methane gas as a by-product of anaerobic cellular respiration. • Thermophiles are organisms that can live in water that is very hot (>220ºF) and/or very acidic (<pH 2). • Extreme halophiles are organisms that thrive in water ten times saltier than the ocean; and uses salt (NaCl) to produce energy.

9. Eubacteria • All of the other prokaryotes that may be decomposers, parasites, a symbiont (lives within other creatures andprovides them benefits), or photosynthetic • Have strong cell walls made with peptidoglycan • Less complex genetic make-up • Live in most habitats, except the extreme ones of archaebacteria

10. Kingdom Protista • A eukaryote that lacks complex organ system and have a visible nucleus • Lives in moist environments • Unicellular, multicellular, and some are colonial • Autotrophs or heterotrophs • Major phyla include: myxomycota, rhizopoda, ciliophora, euglenophyta, bacillariophyta, phaeophyta, and chlorphyta

11. Kingdom Fungi • Earth’s decomposers • Heterotrophs that do not move from place to place • Either a unicellular or multicellular eukaryote • Absorbs nutrients from dead or decaying organisms • Has cell walls made of chitin-a tough, flexible carbohydrate

12. Kingdom Plantae • Multicellular, photosynthetic eukaryotes • None move from place to place • Cells contain chloroplasts • Cell walls made of cellulose • Organized into tissues and organ systems

13. Kingdom Animalia • Multicellularheterotrophs • Nearly all are able to move from place to place • Do not have cell walls • Cells organized into tissues and organ systems