Taxonomy

Classification & taxonomy

Classification is the grouping of objects or information based on similarities.

Taxonomy is the branch of biology concerned with the grouping and naming of organisms.

How living things are classified Organisms are grouped into groups called

taxa, each one larger than the previous one.

The smaller the taxon, the smaller the number of organisms in that group. These organisms share greater similarity to each other than those in the larger taxa.

Example: Come up with a classification system

to classify students in this class. Think big to small Ex. We are all Americans all the way to

students in room L309 Americans Texans Residents of Tarrant County Residents of Colleyville Attend CHHS Biology students Biology students in Mrs. Kays class Biology students in Mrs. Kays 4th period class

Least specific

Most specific

Classification System Did King Phillip Come Over For Good

Spaghetti? Domain Kingdom Phylum Class Order Family Genus Species

Domain This is the largest taxon. All organisms are placed in 1 of 3 groups. A group of related kingdoms.

3 Domains: Bacteria, Archae and Eukarya

Example: Humans are members of the Domain Eukarya along with all other eukaryotic organisms

Kingdom

This is the second largest taxon. All organisms are placed in 1 of 6 groups

based on their cell structure. A group of related phyla.

6 Kingdoms: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia

Ex: Humans are members of the kingdom Animalia along with all other multicellular, heterotrophic eukaryotes

Phylum (pl. phyla)

A smaller subcategory of a kingdom. A group of related classes.

Ex: Humans are members of the phylum cordata along with all other organisms that have a backbone

Class

A smaller subcategory of a phylum. A group of related orders.

Ex: Humans are members of the class mammalia, along with all other organisms who have mammary glands and hair

Order

A smaller subcategory of a class. A group of related families.

Ex: Humans are members of the order primates, along with all other primates

Family

A smaller subcategory of an order. A group of related genera.

Ex: Humans are members of the family hominidae along with all other great apes

Genus (pl. genera)

A smaller subcategory of a family. A group of related species.

Ex: Humans are members of the genus Homo along with all other organisms that have specific and specialized development of memory/learning/teaching/learning application

Species

A smaller subcategory of a genus. A population of interbreeding organisms

capable of producing fertile offspring.

Ex: Humans are members of the species sapiens, which includes only humans as we know them today

Binomial nomenclature

Carl Linnaeus’ System of naming organisms

2-word classification system for naming organisms.

The first word is the genus name. The second word is the species name. All scientific names are in Latin.

Binomial nomenclature When writing an organism’s scientific

name, the genus (first word) should be capitalized and species (second word) should be lower case and both should be italicized or underlined Ex: Homo sapiens

Scientific names can also be abbreviated G. species Ex. H. Sapiens

The 6 Kingdoms

Kingdom descriptions

EACH SLIDE WILL FOLLOW THE FOLLOWING FORMAT:

Number of cells Characteristics Reproduction Examples of Organisms

Note: Prokaryotes are simple, single-celled organisms with no nucleus. Eukaryotes are more complex organisms that can be either single cell or multicellular and contain a nucleus along with other specialized structures

Archaebacteria

Single-celled, prokaryotes Has cell wall but no nucleus Lives without oxygen in extreme

environments Reproduce asexually Ex: Methanogens, halophiles, and

thermophiles

Archaebacteria

Eubacteria Single-celled, prokaryotes Has cell wall (differs slightly from wall of

archaebacteria), but no nucleus Reproduce asexually Ex: Bacteria, blue-green algae

Eubacteria

Protista

Single-celled or multicellular, eukaryotes Has nucleus and membrane May or may not have cell wall Can be either autotrophs or heterotrophs Move by cilia, flagella or pseudopods Normally reproduce asexually but can

reproduce sexually when under stress Ex: Euglenas, single-celled algae, amebas,

paramecia

Protista

Paramecium

Euglena

Amoeba

Fungi Most are multicellular, the only single celled fungi

are yeasts, eukaryotes Has cell wall that contains chitin, nucleus and

membrane Made of slender strands of cells packed together

called hyphae Heterotrophs, do not ingest their food, instead

secrete digestive enzymes onto whatever they are growing on

Reproduce asexually and sexually Types of fungi

Zygomycetes (bread mold) Basidiomycetes (mushrooms) Ascomycetes (fungi that form sexual spores)

Fungi

Mushroom

Yeast cells

Plantae Multicellular with specialized cells and tissues.

Eukaryotes Has cell wall made of cellulose, nucleus,

membrane and chloroplasts (the site of photosynthesis)

Autotrophs, undergo photosynthesis Rooted to the ground so they can’t move Reproduce either sexually or asexually Types of plants

Nonvascular plants (mosses) Seedless vascular plants (ferns) Nonflowering seed plants (pine trees) Flowering seed plants (roses, grasses and fruits)

Plantae

FernFlower

Moss Green algae

Animalia Multicellular with specialized cells and tissues,

eukaryotes Has nucleus and membrane Heterotrophs, undergo cellular respiration Move using a variety of methods including walking,

running and flying Reproduce sexually Types of animals (99% of animals are

invertebrates) Sponges and cnidarians (jellyfish, sea anemones and

coral) Mollusks (snails, oysters and squid) Worms (earthworms) Arthropods (insects and spiders) Echinoderms (sea stars, sea urchin and sand dollars) Vertebrates (fish, mammals, birds and amphibians)

Animalia

Evolutionary History Classification based on similarities should be

based on an organism’s phylogeny, or evolutionary history Remember homologous structures are evidence of a

common ancestor while analogous structures are not Cladistics is the method of inferring relationships

based on shared characters Ancestral character: a character that evolved from a

common ancestor Ex: backbone in birds and mammals

Derived character: evolved in an ancestor of one group but not another

Ex: feathers evolved in birds but non mammals

Evolutionary History A cladogram is a branching diagram that

shows evolutionary relationships among groups of organisms As groups evolve, new characters appear that

were not present in earlier organisms

Cladogram

Hagfish do not have jaws while every organismPast that point on the cladogram does have jaws

Hagfish, Perch, salamanders, lizards and Pigeons have neither fur nor mammary glands while mice and chimps have both characters

Dichotomous Key The identification of biological organisms can be greatly

simplified using tools such as dichotomous keys. A dichotomous key is an organized set of couplets of

mutually exclusive characteristics of biological organisms. You simply compare the characteristics of an unknown

organism against an appropriate dichotomous key. These keys will begin with general characteristics and lead to couplets indicating progressively specific characteristics. If the organism falls into one category, you go to the next indicated couplet.

By following the key and making the correct choices, you should be able to identify your specimen to the indicated taxonomic level. 

Dichotomous Key Example: Use the Key to identify

this alien1) a. The creature has a large wide

head….. Go to 2b. the creature has a small narrow head…. Go to 3

Narrow Head-go to number 3

Dichotomous Key3) a. The creature has no antennae…. Go to

4 b. The creature has antennae… Go to 5

Has Antennae- Go to number 5

Dichotomous Key5) a. Creature has 2 eyes… go to 6 b. Creature has 1 eye….. Narrowus

Cylops

6) a. Creature has a mouth… go to 7 b. Creature has no mouth… go to 8

2 eyes-go to 6 Mouth

-go to 8

Dichotomous Key8) a. There are spikes on the left leg….

Narrowus portus b. There are no spikes at all…. Narrowus

plainus

Spikes on the left leg- Your creature is Narrowus portus!