Chapter 17 – Organizing Life’s Diversity I.Classification – grouping of objects or organisms based on a set of criteria; 2 scientists A. Aristotle (394-322.

Chapter 17 – Organizing Life’s Diversity

I. Classification – grouping of objects or organisms based on a set of criteria; 2 scientists

A. Aristotle (394-322 B.C.):

Greek philosopher who

grouped organisms aseither plants or

animals

B. Carolus Linnaeus (1707-1778) – Swedish naturalist who grouped organisms based on morphology, behavior, & habitat

1. Taxonomy – branch of Biology where species are identified, named, & classified based on natural relationships

II. Binomial Nomenclature – a system that gives each species a scientific name that has 2 parts

A. 1st part: genus name; capitalized

2nd part: specific epithet/name; it IDs the species;

lowercased

B. Writing Scientific names 1. italicized when typed:

Homo sapiens2. in handwriting: Homo

sapiens

C. Latin is the language of Binomial Nomenclature – why?

It is no longer used in conversation and, therefore, does not change

D. Common names are confusing & vary in use

1. A starfish isn’t a fish2. A sea horse is a fish, not a horse3. Sea cucumbers are not plants

III. Taxonomic Categories – these are a nested, hierarchical system, where each category is contained within another from broadest to

most specific

A. The broader the characteristics, the more species the taxon contains

1. Species – smallest taxon; organisms that are able to interbreed & produce fertile offspring in a natural setting

2. Genus – group of species that are closely related & share a common ancestor

3. Family – group of similar, related genera (plural of genus)

4. Order – group of related families

5. Class – group of related orders

6. Phylum / Division – group of related classes

7. Kingdom – group of related phyla/divisions

8. Domain – largest taxon; group of related Kingdoms

B. Example in Humans:

Taxon Name Shared with?

D-Dear Eukarya all other organisms w/ nuclei & organelles in their cells

K-King Animalia all other animals

P-Phillip Chordata with a spinal cord

C-Came Mammalia hairy; young are fed milk

O-Over Primate opposable thumbs

F-For Hominidae primates w/ social skills & complex intelligence

G-Good Homo all humans, including those that are extinct

S-Spaghetti

sapiens us – the only humans alive

C. Dichotomous Key – a key made up of sets of numbered yes/no statements

1. Has green colored body ......go to 2

Has purple colored body ..... go to 4

2. Has 4 legs .....go to 3

Has 8 legs .......... Deerus octagis

3. Has a tail ........ Deerus pestis

Does not have a tail ..... Deerus magnus

4. Has a pointy hump ...... Deerus humpis

Does not have a pointy hump.....go to 5

5. Has ears .........Deerus purplinis

  Does not have ears ......Deerus deafus

IV. Phylogeny – the evolutionary history of a species, based on characters (inherited, varied features)

A. Morphological – similar parts suggest a relationship

beaks of Galapagos finches

bones in vertebrate limbs

B. Biochemical – similar amino acids & nucleotides in DNA suggest a

relationship

1. Cauliflower & Broccoli look different, but have almost identical DNA (mustard)

C. Cladogram – a branching diagram that represents the proposed phylogeny or evolutionary history of a species or group

D. The 3 Domains w/ 6 Kingdoms – differ in cell type & structure (pg. 502)

Domain Kingdom Characteristics

Bacteria (Eu)Bacteria cell walls w/ peptidoglycan,unicellular

Archaea Archaea(bacteria) cell walls w/o PG, unicellular

Eukarya Protista cell walls w/ cellulose in some, unicellular or multicellular

Fungi cell walls w/ chitin, mostly multicellular,

heterotrophs

Plantae cell walls w/ cellulose, multicellular, autotrophs

Animalia no cell walls, multicellular,heterotrophs

Eu

kary

ote

sP

rokary

ote

s

Au

totro

ph

s OR

Hete

rotro

ph

s

Evolution of the 6 Kingdoms of Life

Common Ancestor

Older, Less

Complex

Newer, More

Complex

ArchaeaBacteria

Protista

Animalia FungiPlantae

The 6 Kingdoms of Life