1.3-Kingdoms and Domains SBI3U1

Recall: TAXONOMY is the study of . . . DISCOVERING NAMING DESCRIBING CLASSIFYING In order to describe and classify a new species, one must compare them to other organisms. ORGANISMS Used to better understand biodiversity

Remember….. Organisms are classified based on 8 taxonomic categories: Domain Kingdom Phylum Class Order Family Genus Species Now let’s focus on these!

Classifying Species ( Kingdoms & Domains) When classifying species , scientists look for similarities and differences between organisms at a higher rank such as domain and kingdoms When scientists look at similarities they look at the organisms cell type, cell number & DNA sequence.

Animals Plants Fungi Protists Bacteria Archaea Six Kingdoms are… Animals Plants Fungi Protists Bacteria Archaea

Six Kingdoms Advances in microscopy and molecular biology have increased the number of kingdoms from two in the 1800s to six in 1990s

The info used to categorize different kingdoms: Cell Type Number of Cells Cell Wall Material Nutrition Type of Reproduction *Note: cell type and number of cells are primary distinction factor.

1. Cell Types Prokaryotes (before nucleus) : small, simple cell without a membrane bound nucleus ( NO NUCLEUS) Eukaryotes (true nucleus) : ~1000X larger, complex cell with a membrane bound nucleus (CONTAINS NUCLEUS)

2. Number of Cells Multicellular organisms are made of more than one eukaryotic cell E.g. Cats, plants, humans Single-cell (or unicellular) organisms are usually made of prokaryotic cells E.g. Bacteria

3. Cell Wall Materials Cell wall material varies btw. organisms Depending on type of material, organisms are classified in different domains and kingdoms Chitin (fungi) Peptidoglycan is a polymer of animo acids and sugars Chitin is a polysaccharide that contains nitrogen Cellulose is a polysaccharide with B-glucose (indigestible in humans) Cellulose (plants) Peptidoglycan (bacteria)

4. Nutrition Autotrophs: organisms that capture energy from sunlight to produce their own food. Heterotrophs: organisms that get nutrients and energy by consuming other organisms. Autotroph Heterotroph

5. Reproduction Asexual: offspring arise from a single parent, and inherit the genes of that parent only Sexual: genetic material of two parents are combined to create an offspring Asexual Reproduction

There are 3 Domains Bacteria Archaea Eukarya ( protista, fungi, plantae, animalia)

Dichotomous Keys Identification tool Series of two-part choices that lead the user to the correct identification of an organism Used by scientist with a specimen that is unknown

Dichotomous Keys To classify an organism, scientists begin at the domain level and work through many sequential questions with only two possible answer choices to reach a genus/species level of identification. Most questions involve anatomical and structural analysis. In some cases, only the kingdom taxon is required.

Dichotomous Key (pg. 27) 1a. Skin dry and warty...American toad 1b. Skin not dry and warty...go to 2 2a. Toes with “sticky pads”...go to 3 2b. Toes without sticky pads...go to 4 3a. Brown, <2 cm, a darker X-shaped mark on the back...spring peeper 3b. Grey or green, yellow under the legs...eastern grey treefrog 4a. Back without a pair of ridges...go to 5 4b. Back with a pair of ridges...go to 6 5a. Mottled pattern, with mammal-like odour...mink frog 5b. Unmottled green pattern; to 15 cm...bullfrog 6a. Back with large round or squarish spots...go to 7 6b. Back unspotted (or with a few small spots)...go to 8 7a. Spot round...leopard frog 7b. Spots squarish...pickerel frog 8a. Predominantly green colour...green frog 8b. Brown, with a dark mask through the eye...wood frog

Dichotomous Keys Often, the key is turned into a visual

Dichotomous Key Game: http://www.execulink.com/~ekimmel/dichot omous_bugs.swf

HOMEWORK -Read and make notes 1.3 pgs. 24-29 -Complete pg. 30 Q# 2, 6, 7, 8 -Dichotomous Key Activity TBA