Today’s Bell Ringer We watched a video on “What Plant Talk About” 8 March Today’s Bell Ringer We watched a video on “What Plant Talk About” https://www.youtube.com/watch?v=CrrSAc-vjG4

Today’s Bell Ringer Please define: Species – Taxonomy – 9 March Today’s Bell Ringer Taxonomic relationships were originally based on external morphology. Today, taxonomy is based on molecular similarities and evolutionary relationships. Please define: Species – Taxonomy – Binominal nomenclature – (pg. 519) Cladogram – Phylogeny –

http://www.ted.com/talks/rachel_sussman_the_world_s_oldest_living_things

Use the organisms on your desk to determine which ones are most related. For Crabs: Species - Genus - Family - Portunidae Order - Decapoda Class - Malacostraca Phylum – Arthropoda Kingdom Domain For Fish: Species - Genus - Family - Pomacanthida Order – Perciformes Class - Actinopterygii Phylum – Arthropoda Kingdom Domain

Domain

EUKARYA BACTERIA ARCHAEA Land plants Dinoflagellates Green algae Forams Ciliates Diatoms Red algae Amoebas Cellular slime molds Euglena Trypanosomes Animals Leishmania Fungi Sulfolobus Green nonsulfur bacteria Thermophiles (Mitochondrion) Figure 26.21 The three domains of life Spirochetes Halophiles Chlamydia COMMON ANCESTOR OF ALL LIFE Green sulfur bacteria BACTERIA Methanobacterium Cyanobacteria ARCHAEA (Plastids, including chloroplasts)

Binomial nomenclature is a two-part scientific naming system. uses Latin words scientific names always written in italics two parts are the genus name and species descriptor

Cladistics is a common method to make evolutionary trees. classification based on common ancestry species placed in order that they descended from common ancestor

A cladogram is an evolutionary tree made using cladistics. A clade is a group of species that shares a common ancestor. Each species in a clade shares some traits with the ancestor. Each species in a clade has traits that have changed.

Molecular evidence reveals species’ relatedness. Molecular data may confirm classification based on physical similarities. Molecular data may lead scientists to propose a new classification. DNA is usually given the last word by scientists.

The three domains in the tree of life are Bacteria, Archaea, and Eukarya. Domains are above the kingdom level. Carl Woese: studied rRNA of prokaryotes and found they were two separate groups, genetically speaking domain model more clearly shows prokaryotic diversity

Domain Bacteria includes prokaryotes in the kingdom Bacteria. one of largest groups on Earth classified by shape, need for oxygen, and diseases caused

Domain Archaea includes prokaryotes in the kingdom Archaea. cell walls chemically different from bacteria differences discovered by studying RNA known for living in extreme environments

Bacteria and archaea can be difficult to classify. transfer genes among themselves outside of reproduction blurs the line between “species” more research needed to understand prokaryotes bridge to transfer DNA

Domain Eukarya includes all eukaryotes. kingdom Protista

Domain Eukarya includes all eukaryotes. kingdom Protista kingdom Plantae

Domain Eukarya includes all eukaryotes. kingdom Protista kingdom Plantae kingdom Fungi

Domain Eukarya includes all eukaryotes. kingdom Protista kingdom Plantae kingdom Fungi kingdom Animalia

Organisms can be classified based on physical similarities.

Linnaeus developed the scientific naming system still used today. Taxonomy is the science of naming and classifying organisms. White oak: Quercus alba A taxon is a group of organisms in a classification system.

A genus includes one or more physically similar species. Species in the same genus are thought to be closely related. Genus name is always capitalized and italisized. A species descriptor is the second part of a scientific name. always lowercase always follows genus name; never written alone Tyto alba

Advantages: unique name for each species, scientists around the world recognize them Some species have very similar common names. Some species have many common names.

Linnaeus’ classification system has seven levels, called taxa. Each level is included in the level above it. Levels get increasingly specific from kingdom to species.

The Linnaean classification system has limitations. Linnaeus taxonomy doesn’t account for molecular evidence. The technology didn’t exist during Linneaus’ time. Linnaean system based only on physical similarities.

Genetic similarities more accurately show evolutionary relationships. Physical similarities are not always the result of close relationships. Genetic similarities more accurately show evolutionary relationships. http://www.ted.com/talks/jonathan_drori_the_beautiful_tricks_of_flowers