Ch.17 – Organizing Life’s Diversity 17.1 – History of Classification

Taxonomy – branch of biology concerned with identifying, naming, and classifying species

Based on a system developed by Carolus

Linnaeus in 1748

He also developed a two-part naming system for every

species

Linnaeus’ system involved classifying organisms in a series of groups from

large and general to smaller and more specific according to physical

characteristics

Ch.17 – Organizing Life’s Diversity 17.1 – History of Classification

Animalia Animalia

Chordata Chordata

Mamalia Mamalia

Primata Primata

Hominidae Hominidae

Homo Homo

Sapiens Sapiens

Used as the scientific names for all species (Binomial Nomenclature)

Eukaryotic, heterotrophic, multicellular

Eukaryotic, heterotrophic, multicellular

VertebratesVertebrates

Milk-producing, fur/hair

covered

Milk-producing, fur/hair

covered

Short snouts, stereoscopic vision, nails not claws, 4 types of teeth

Short snouts, stereoscopic vision, nails not claws, 4 types of teeth

Bipedal, large frontal

lobes of brain

Bipedal, large frontal

lobes of brain

Larger brain (>1000cc), upright forehead, shorter arms, longer

legs, language, culture

Larger brain (>1000cc), upright forehead, shorter arms, longer

legs, language, culture

High forehead, small teeth and jaw, defined chin, and

ability to create and appreciate art/symbols

High forehead, small teeth and jaw, defined chin, and

ability to create and appreciate art/symbols

Human Classification

Ch.17 – Organizing Life’s Diversity 17.2 – Modern Classification

Phylogenetic tree - shows evolutionary

relationships based on similarities and

differences in physical and/or genetic

characteristics.

There is presumed to be a common ancestor at each node and the

distance between nodes indicates the passage of time

Species are classified today according to physical and genetic characteristics

Ch.17 – Organizing Life’s Diversity 17.2 – Modern Classification

Cladogram - shows one branch of a phylogenetic tree and focuses mainly on homologous structures of the organisms

Derived trait – A trait not present in the last common ancestor being considered

Ancestral trait – Traits retained from common

ancestors

Ch.17 – Organizing Life’s Diversity 17.3 – Domains and Kingdoms

The 3 Domains and 6 Kingdoms

PlantaePlantae AnimaliaAnimaliaFungiFungi

ProtistaProtista

EubacteriaEubacteriaArchaebacteria

Archaea

Archaea

Bacteria

Eukarya

Eukarya

Ch.17 – Organizing Life’s Diversity 17.3 – Domains and Kingdoms

Archaebacteria Eubacteria Protista

Fungi Plantae Animalia

ProkaryoticUnicellularHetero- or

Autotrophic

-Live in extreme environments

ProkaryoticUnicellularHetero- or

Autotrophic

-Live in extreme environments

ProkaryoticUnicellularHetero- or

Autotrophic

-Most bacteria found on Earth

ProkaryoticUnicellularHetero- or

Autotrophic

-Most bacteria found on Earth

EukaryoticUni- or Multicellular

Hetero- or Autotrophic

-Usually found in aquatic environments

EukaryoticUni- or Multicellular

Hetero- or Autotrophic

-Usually found in aquatic environments

EukaryoticUni- or Multicellular

Heterotrophic(Decomposers)-Absorb nutrients from other organic

material

EukaryoticUni- or Multicellular

Heterotrophic(Decomposers)-Absorb nutrients from other organic

material

EukaryoticMulticellularAutotrophic

-Have cells organized into tissues

-Most are immobile

EukaryoticMulticellularAutotrophic

-Have cells organized into tissues

-Most are immobile

EukaryoticMulticellular

Heterotrophic-Have tissues

organized into organs and organ systems-Most are mobile

EukaryoticMulticellular

Heterotrophic-Have tissues

organized into organs and organ systems-Most are mobile

Ch.17 – Organizing Life’s Diversity 17.3 – Domains and Kingdoms

What about Viruses?

-Viruses are non-living. -They are DNA or RNA surrounded by a protein coat (capsid) and

are sometimes enclosed within a membrane

-A virus needs a host to reproduce

-Outside of a host a virus is metabolically inert

-The virus inserts its genetic material into the host, taking over the host’s functions.

-An infected cell creates more viral protein and genetic

material.

Viruses containing RNA are called retroviruses

HIV (a retrovirus)

HIV (a retrovirus)

Ch.17 – Organizing Life’s Diversity 17.3 – Domains and Kingdoms

What about Viruses?

-A virus may remain

dormant for a period of time

causing no changes in the host cell, called the lysogenic

phase

-But when stimulated, it

enters the lytic phase:

new viruses are formed, self-

assemble, and burst out of the host cell, killing

the cell and going on to

infect other cells

Viral Diseases-Common Cold

-Influenza-Chicken Pox

-Herpes (I & II)-AIDS