Unit 1: Diversity of Living Things

Classification of Species Species can be classified by looking at: Morphology Based on structural features Biology Based on the ability to produce fertile offspring Phylogeny Based on evolutionary history

Naming of Organisms Carolus Linnaeus classified organisms according to their structural similarities: this is called TAXONOMY Each group to which Linnaeus assigned organisms is called a TAXA (singular is TAXON) Modern taxonomy groups based on their evolutionary relatedness: this is called PHYLOGENY Organisms share common ancestry if they show similar stages of embryological development and anatomical structures.

The system we use is called the binomial nomenclature To understand this naming system, you need to know the RANK breakdown http://upload.wikimedia.org/wikipedia/commons/6/68/Carl_von_Linné.jpg

Ranks

Example: “Killer Whale” Cetacea  whales dolphin family

To be a part of a taxa, an organism has to have the necessary characteristics For example, the Killer Whale is a chordata. What characteristic does it have to have a chordata?

Scientific names use binomial nomenclature They are always written in italics!! If written by hand, then we UNDERLINE both parts of the name The first word is the genus name The second word is the species name Ex. Homo sapiens  Homo sapiens

The taxon “species” is the smallest group and it contains only a single type of organism. The organisms in a species are most like one another—except for sexual or growth stage differences, the individuals of a species have the same body or physiological morphology.

Organisms in the same species can interbreed to produce viable offspring.

These cannot....

Similar species are grouped in the same genus Example: the bobcat and the housecat are in the genus Felis Bobcat would rather have housecat as meal instead of mate with it

Genera are grouped to form families. This group’s family is Felidae

Families are grouped into Orders Families are grouped into Orders. These organisms are in the order Carnivora

Orders are then placed in Classes Orders are then placed in Classes. These organisms are in the class Mammalia Mammals  hairy, produce milk

Classes are grouped into Phyla Classes are grouped into Phyla. These organisms are in the phyla Chordata in the Kingdom Animalia

6 Kingdoms Archaebacteria Eubacteria Protista Fungi Plantae Animalia

Classifying Kingdoms based on... Nutrition Heterotrophic -consumes living or dead organisms to obtain energy Autotrophic -uses sun’s energy -makes own food # of cells Unicellular -one cell Multicellular -more than one cell Reproduction Asexual -offspring produced from a single parent (genetically identical to parent Sexual -production of offspring from fusion of 2 sex cells (offspring differ from parents)

Classifying Kingdoms Habitat Cell Type -where does the organism live? Prokaryotic Eukaryotic -circular chromosome -no membrane bound organelles (e.g. no true nucleus) -very small (less than 2 um) -reproduce by binary fission -double stranded chromosomes in nucleus -membrane bound organelles -larger (10-100 um) -reproduce by mitosis or meiosis

Homework: Read pg 15 Pg 16 #5-10 What are domains? Hint: pg 26