Organizing Life’s Diversity Chapter 17 Organizing Life’s Diversity

Section 1

Biologist use a system of classification to organize information about the diversity of living things. Classification is defines as: the grouping of objects or organisms based on a set of criteria. How did Aristotle classify organisms? What made his thought different from Darwin’s Theory of Evolution? Aristotle classified organisms as either animals or plants. Aristotle’s system was based on his view that species are distinct, separate and unchanging. He did not account for evolutionary relationships Who is Carolus Linnaeus? How were his ideas similar to Aristotle? Carolus Linnaeus was a Swedish naturalist. He broadened Aristotle’s classification to a formalized scientific system. This was based on observational studies of the morphology and the behavior of organisms. Taxonomy is defined as: discipline of biology concerned with identifying, naming and classifying species based on natural relationships.

What was Linnaeus’s method called fro naming organisms What was Linnaeus’s method called fro naming organisms? What are the two parts of the name? Linnaues’s method for naming organisms is called binomial nomenclature The two parts of the name are the Genius species When writing a scientific name, what are the four rules to follow? When writing the genius name the 1st letter is capitalized, the species name is lowercase When printed in a book, magazine, etc. the Genius species name should be italicized When written by hand bothe parts should be underlined: Genius species After the completed scientific name has been written once, it can then be abbreviated Homo sapiens to H. sapiens

Taxon is defined as: a named group of organisms (plural taxa) How are taxa arranged? They are arranged from very broad to very specific Genius is defined as: group of species closely related tgat share a common ancestor Family is defined as: next higher taxon – similar related genera Order is defined as: contains related families Class is defined as: contains related orders Phylum/Division is defined as: contains related class; division is used in plants and bacteria, phylum is used for animals, fungi, and Protista Kingdom is defined as: composed of related phyla or divisions Domain is defined as: broadest of all taxa and contain one or more kingdoms

What are the 7 (8) Taxonomic categories. Which is the Largest What are the 7 (8) Taxonomic categories? Which is the Largest? (domain), kingdom, phylum, class, order, family, genius, species – domain is the largest What is a dichotomous key? Key based on a series of choices between alternate characteristics. How do scientist group organisms? Scientist group organisms based on their characteristics What is the difference between taxonomy and systematics? Taxonomy deals with classifying and naming organisms. Systematics deals with the evolutionary relationships and is concerned about the amount of evolutionary change that may have occurred.

Section 2

Aristotle and Linnaeus thought of each species as a distinctly different group of organisms based on physical similarities. The definition of species is called the typological species concept The typological species concept is based on what? Based on the idea that species are unchanging, distinct and natural types. The type of specimen was an individual of the species that best displayed the characteristics of that species. What is the biological species concept? A group of organisms that are able to interbreed and produce fertile offspring in a natural setting. Does not account for extinct species or species that reproduce asexually. What is the phylogenetic species concept? Classification determined by evolutionary history Phylogeny is defined as: the evolutionary history of a species Characters are defined as: inherited features that vary among species

Species Concept Description Limitation Benefit Typological Physical characteristics with a type specimen Alleles produce a wide variety of features in all species Provide detailed record of physical characteristic of many organisms Biological Similar characteristics and ability to interbreed and produce fertile offspring Some different species can interbreed. Doesn’t account for extinct species Working definition applies in most cases, so still used frequently Phylogenetic Classification determined by evolutionary history Evolutionary histories are not know for all species Accounts for extinct species and considers molecular data

What are the two types of characters? Morphological Biochemical What is meant by morphological characters? Size, shape and structure of an organisms. Share morphological characteristics suggest that species are related closely and evolved from a recent common ancestor What are analogous structures? They have the same function but different underlying construction What are homologous characters? Might differ in function, but show anatomical similarity What are some examples of biochemical characters and what are they used for? Amino acids and nucleotides – help determine evolutionary relationships among species; chromosome # and structure – help determine species similarities

A molecular clock is defined as: model that is used to compare DNA sequences from 2 different species to estimate how long the species have been evolving since the diverged from a common ancestor What are molecular clock used for? To compare DNA sequences or amino acid sequences of genes that are shared by different species. The definition of Cladistics is: method that classifies organisms according to the order that they diverged from a common ancestor. What are the two types of characters used in cladistics analysis and what is the difference between the two? Ancestral Character – found within the entire line od descent of a group of organisms Derived Character – present in members of one group of the line but not in the common ancestor

A cladogram is: branching diagram that represents the proposed phylogeny or evolutionary history of a species or group What is a cladogram similar to and what is another name for a cladogram? Cladograms are similar to pedigrees Another name for a cladogram is clades

Section 3

What is the broadest category in the classification system? Domain What are the 3 Domians Bacteria Archaea Eukarya What are the six kingdoms within the 3 domains? Archaebacteria Protista Fungi Plantae Animalia

How are organisms classified into domains How are organisms classified into domains? They are classified into domains according to cell type and structure How are organisms classified into kingdoms? They are classified into kingdoms according to cell type. Structure and nutrition Bacteria are members of which domain and kingdom? Are they prokaryotes or eukaryotes? Bacteria are in Domain Bacteria they are in kingdom Bacteria Some bacteria can be aerobic (needs O2) or anaerobic (die in presence of O2). Bacteria can also be autotrophic and produce their own food or heterotrophic and get their food from other organisms. Archaea are classified in the domain Archaea, are more ancient that bacteria and are more closely related to eukaryote ancestors. What type of environments do archaea live in? Because of this, what are they know as? They live in boiling hot springs, salty lakes, thermal vents and mud of marshes with no O2. They are know as extremophiles

Eukaryotic are cells that have membrane bound nucleus and other membrane bound organelles Eukaryotes are classified in which domain? Domain Eukarya Which kingdoms are included in Domain Eukarya? Protista, Fungi, Plantae and Animalia Protists are defined as: eukaryotic organisms that can be unicellular, colonial or multicellular. They are members of Kingdom Protista and Domain Eukarya. They do not have organs The three groups are: Algae – plant like protist – kelp – autotrophic (photosynthesis) Protozoans – animal like – amoebas - heterotrophic Fungus like – slime molds and mildews - heterotrophic

Fungus unicellular or multicellular eukaryotes that absorb organic material nutrients from their environment – heterotrophic They belong to kingdom Fungi Heterotrophic Lack motility Cell walls They obtain food by secreting digestive enzymes into their food source and then absorb digested materials directly into the cell

Plants – kingdom Plantae There are 250,000 + species of plants They are multicellular Contain chloroplast Cell wall made of cellulous Autotrophic (photosynthesis) Animals – Kingdom Animalia 1 million + species make up kingdom Animalia All animals are heterotrophic, multicellular eukaryotes, most are motile Animals do not have cell walss Coral is an example of animal that lacks motility

What is a virus made of? They are made of nucleic acid surrounded by a protein coat They do not possess cells They are not considered living They are not placed in the biological classification system because they are non-living Protist Fungi Plant-like, animal like, fungus-like Unicellular or multicellular Unicellular, multicellular, colonial Cell wall contain chitin No organs Consist of Hyphae – responsible for growth, feeding and reproduction Heterotrophic and autotrophic heterotrophic