Classification of Living Things

Definitions Taxonomy – the science of classifying organisms based on biological similarities Carolus Linnaeus – the father of taxonomy Binomial nomenclature – the way that organisms are named using two word Latin descriptions Kingdom – the most general description of living things (6) Phylum – the second level of classification

Definitions cont… Class – the third level of classification Order – the fourth level of classification Family – the fifth level of classification Genus – a Latin name that describes a specific organism Species – the most specific level of classification

Definitions cont….. Eubacteria – a unicellular kingdom of bacteria that have a cell wall and a cell membrane made of carbohydrates Archaebacteria – a unicellular kingdom of bacteria that are way different than the eubacterias Plantae - multicellular kingdom of organisms that include flowering plants, mosses, and ferns Animalia – a multicellular kingdom of organisms that includes an incredible diversity of animals Fungi – a multicellular kingdom of organisms that can not move to get their food

Definitions cont…. Protista – unicellular kingdom of organisms that contain organelles and a nucleus Dichotomous Key – a tool used by scientists to determine the scientific name of an organism Scientific name - the name given to an organism using the genus and species name Common name – a nickname given to an organism classification – placing organisms into similar groups

The "Nuts and Bolts" of Taxonomy and Classification

Why Classify? There are more than 2.5 million different living things on earth. Millions more have not yet been discovered. Life is diverse and needs to be organized. It is organized so that scientists all over the world have a universal method of classifying. Organisms are placed into groups with biological similarities.

History of Classification: Aristotle - 2000 years ago Plant or Animal Stem differences Land dweller Water dweller Air dweller

Problems with this early system: Some plants and animals could not be classified using this system. People also used common names. Common names - don’t describe things accurately Example: Jellyfish is not a fish

Same common name for different species Maple Trees = Silver Maple, Sugar Maple, & Red Maple are each different species

Cougar, Mountain Lion, Puma By the 1700’s scientists realized that common names were too confusing. They vary among languages and even regions.

Carolus Linnaeus 1707 - 1778 Binomial Nomenclature “two names” All organisms are called by their Genus and species 1707 - 1778

Canis lupus

Canis latrans

Canis domesticus

How are organisms classified? Kingdom (6) Phylum Class Order Family Genus Species The least specific The most specific

The Six Kingdoms Archaebacteria Eubacteria Protists Fungi Animalia Plantae

Kingdom of bacteria that have no nucleus Eubacteria Kingdom of bacteria that have no nucleus

Eubacteria Larger of the two prokaryote kingdoms. Surrounded by a cell wall made of carbohydrates. Wide range of organisms; simple to elaborate Range from living in soil to infectious bacteria. Such a large range; number of phyla is debated.

Examples of Eubacteria: Cyanobacteria (blue-green bacteria) Photosynthetic Found throughout the world; salt water to freshwater Some species survive in hot springs, or in the arctic Usually a pioneer species; colonization after volcanoes

Kingdom of bacteria that are more developed than the eubacteria Archaebacteria Kingdom of bacteria that are more developed than the eubacteria

Archaebacteria Lack an important carbohydrate found in the cell walls of eubacteria. Differ in lipids, ribosomes, and gene sequences. Organisms that live in extremely harsh environments- thick mud, digestive tracts, salty environments, and thermal vents.

Kingdom of unicellular organisms Protista Kingdom of unicellular organisms

Single-celled eukaryotic organisms Divided into three groups: Protista Single-celled eukaryotic organisms Divided into three groups: Animal-like protists Plant-like protists Fungus-like protists Examples: amoeba, paramecium, euglena, slime mold

The mushrooms and molds Fungi The mushrooms and molds

Build cell walls that do not contain cellulose. Fungi Build cell walls that do not contain cellulose. Heterotrophic- DO NOT CARRY OUT PHOTOSYNTHESIS Examples: yeast, molds, mushrooms

Plantae Kingdom of plants

Plantae Multicellular Cell walls contain cellulose Autotrophic- can carry out photosynthesis using chlorophyll Examples: flowering plants, mosses, ferns, multicellular algae

Animalia Kingdom of animals

Cell membranes/ no cell walls Includes incredible diversity Animalia Multicellular Heterotrophic Cell membranes/ no cell walls Includes incredible diversity

Memorize the levels of classification in order. A good way to remember them is…… King Pete Caught Over Five Green Snakes Kids Playing Catch On Freeways Get Squished You can also come up with your own sentence to help you remember them in order. Memorize all 6 kingdoms

Carolus Linnaeus 1707 - 1778

The Father of Taxonomy His system for naming, ranking, and classifying organisms is still in wide use today (with many changes). His ideas on classification have influenced generations of biologists during and after his own lifetime, even those opposed to the philosophical and theological roots of his work.

Let's take a look at how it works.. Classification Carolus Linnaeus developed the classification system His system was called binomial nomenclature Organisms were named using the Latin genus and species names An international committee keeps track of all new names A Dichotomous Key is used by scientists to research new organisms and to figure out scientific names Let's take a look at how it works..

Kingdom;Animalia

Phylum; Chordata

Class; Mammalia

Order; Carnivora

Family; Ursidae

Genus; Ursus or Ursus

Species; arctos or arctos Scientific Name = Ursus arctos

Ursus arctos Scientific Name = or Ursus arctos Species Genus Common name = Grizzly Bear

Writing a scientific name The scientific name is equal to binomial nomenclature The genus and species name are always used The genus name is always written first It always begins with a capital letter The species name is written right after the genus name It always begins with a lower case letter Both words must be underlined or written in italics Studentia lazyrentus

Number your paper from 1 to 6 Name each Kingdom Number your paper from 1 to 6 1 5 3 2 6 4

Check your answers Animalia Fungi Archaebacteria Protista Plantae Eubacteria

Dichotomous Key A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts".

Rules when reading a dichotomous key Always read both choices, even if the first seems to be the logical one at first. Be sure you understand the meaning of the terms involved. Do Not Guess. When measurements are given, use a calibrated scale. Do Not Guess. Since living things are always somewhat variable, do not base your conclusion on a single observation. Study several specimens to be sure your specimen is typical. If the choice is not clear, for whatever reason, try both divisions. If you end up with two possible answers, read descriptions of the two choices to help you decide

Dichotomous Key Example 1. a. wings covered by an exoskeleton ………go to step 2 b. wings not covered by an exoskeleton …..go to step 3 2. a. body has a round shape …………….ladybug b. body has an elongated shape ……….grasshopper 3. a. wings point out from the side of the body …….dragonfly b. wings point to the posterior of the body ……….housefly

Notice that there were four organisms to be identified and it only took three steps. There should be one less step than the total number of organisms to be identified in your dichotomous key.

Constructing a dichotomous key Use constant characteristics rather than variable ones. Use measurements rather than terms like "large" and "small". Use characteristics that are generally available to the user of the key rather than seasonal characteristics or those seen only in the field. Make the choice a positive one - something "is" instead of "is not". If possible, start both choices of a pair with the same word. If possible, start different pairs of choices with different words. Precede the descriptive terms with the name of the part to which they apply.