Prokaryotic Cell

Eukaryotic Cell

 Autotrophs capture the light energy from sunlight and convert it to chemical energy they use for food.  Heterotrophs get energy by eating autotrophs or other heterotrophs.  Decomposers, aka saprobes, are heterotrophs that recycle dead organisms by breaking them down.

Phylogeny Systematics Hypothesis Cladistics Derived character Cladogram Dichotomous Key Classification Taxonomy Aristotle Linnaeus Kingdom Phylum Class Order Family Genus Species Common name Scientific name Binomial nomenclature

Taxonomy is the science of grouping and naming organisms. Classification the grouping of information or objects based on similarities.

Why use a dead language? We only know about a fraction of the organisms that exist or have existed on Earth. Taxonomists give a unique scientific name to each species they know about whether it’s alive today or extinct. The scientific name comes from one of two “dead” languages – Latin or ancient Greek.

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Puma

Florida Panther

Cougar

There are at least 50 common names for the animal shown on the previous 7 slides. Common names vary according to region. Soooo……why use a scientific name?

Binomial Nomenclature A two name naming system The Genus name is first, and capitolized The species name is second, and never capitolized Both words are written in italics or underlined (if handwritten) Example: Felis concolor

In addition Formal scientific names should also have a third part, the authority This is an abbreviation of the last name of the person who named it It is not italicized or underlined Example: Quercus alba L.

Taxonomy Phylogeny, the evolutionary history of an organism, is the cornerstone of a branch of biology called systematic taxonomy.

A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms.

Systematics, as systematic taxonomy is commonly called, is the study of the evolution of biological diversity.

Phylogenetic trees are usually based on a combination of these lines of evidence: Fossil record Morphology Embryological patterns of development Chromosomes and DNA

Fossil

Morphology

Homologous Structures

Adaptive Radiation - modifies homologous structures Modifies homologous structures

Analogous Structures - Traits that are morphologically and functionally similar even though there is no common ancestor. Convergent evolution leads to……….

Cladistics Classification system that uses shared derived characters to establish evolutionary relationships A derived character is a feature that developed only in one group Cladistics

Three basic assumptions of cladistics Organisms within a group have a common ancestor There is a bifurcating pattern of cladogenesis Lineages change in characteristics over time

A phylogenetic tree based on a cladistic analysis is called a cladogram. What derived character is shared by all the animals on the cladogram on the next slide?

A key is a device for easily and quickly identifying an unknown organism. The dichotomous key is the most widely used type in biological sciences. The user is presented with a sequence of choices between two statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed. The Dichotomous Key

The Three Domains Domain Archaea – Includes newly discovered cell types – Contains 1 kingdom – the Archaebacteria Domain Bacteria – Includes other members of old kingdom Monera – Has 1 kingdom – the Eubacteria Domain Eukarya – Includes all kingdoms composed of organisms made up of eukaryotic cells – Protista – Fungi – Animalia – Plantae

The major classification levels, from most general to most specific (several of these have subdivisions) A group at any level is a taxon.

Kingdoms are divided into groups called phyla Phyla are subdivided into classes Classes are subdivided into orders Orders are subdivided into families Families are divided into genera Genera contain closely related species Species is unique Categories within Kingdoms