SCI: Biodiversity

Binomial nomenclature

* two-part scientific naming system
* bi = two (genus, species) nomial = name
* nomen = naming clature = system

How are organisms classified?

* can be classified based on physical similarities

Carolus Linnaeus

* developed the binomial nomenclature

Taxonomy

* the science of naming and classfying organisms

Taxon

* group of organisms in a classification system

Genus name

* includes one or more physically similar species

Species descriptor

* second part of a scientific name
* unique descripor that describes the organism, usually an important trait or their habitat

Rules in Binomial nomenclature

* uses latin words (& some latinized greek) because latin is a dead language
* scientific names always in italics when printed and underlined when written
* has two parts - the genus name and species descriptor
* genus name is always capitalized
* species name is always lowercase
* species always follows genus; never written alone

Why was this system developed?

* scientific names help scientists communicate

Who makes the rules for naming organisms?

* International Code for Binomial Nomenclature
* all names must be approved by International Naming Congress (International Zoological Congress)
* this prevents duplicate names

Sardinella tawilis

* Tawilis


* lives in taal lake

Bubalus bubalis carabanensis

* carabao

Jasminum sambac

* sampaguita

Pithecophaga jeffryi

* philippine eagle

Limitations of the system

* doesn’t account for molecular evidence
* technology didn’t exist during Linneaus’ time
* based only on physical similarities

Seven levels of the system

* Domain
* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Species
* each level is included in the level above it
* genetic similarities more accurately show evolutionary relationships

3 Domains of Life

* Archaebacteria
* Bacteria
* Eukarya

Prokaryotic

* cells that lack a nucleus

Eukaryotic

* cells that contain a nucleus

Unicellular

* single-celled; made up of one cell

Multi-cellular

* made up of many cells

Autotrophic

* can make their own food

Heterotrophic

* can NOT make their own food

Archaebacteria

* thought to be the oldest living organisms
* extremophiles
* halophiles - likes salt
* acidophiles - acidic
* thermophiles - can endure extreme heat
* Autotrophic
* chemotrophic - gathers chemicals to make food
* photosynthetic
* cell walls are composed of CELLULOSE
* Archea - means old
* reproduction
* binary fission fragmentation

Bacteria

* mostly heterotrophic
* many are saprotrophs - they obtain food from decaying organic matter
* huge number are parasitic - can cause many diseases
* cells walls made of PEPTIDOGLYCAN
* reproduction
* binary fission - ex: e.coli can double its cells every 20 mins, others are 10 mins and some are 24 hrs
* conjugation (sex pili)

Archaebacteria vs. Eubacteria

Eukarya

* most diverse domain
* came from the greek words “eu” which means true and “karyon” which means nut
* “eu karyon” = true nut = true nucleus
* composed of organisms having “true nucleus”
* according to archeological proofs, eukaryotic cells have started to exist more than 0.6 billion years ago
* has 4 kingdoms - plantae, animalia, fungi, protista

6 Kingdoms of Life

* plantae
* animalia
* fungi
* archeabacteria
* eubacteria
* protista

Kingdom Protista

* Protists
* most are unicellular, others are multicellular
* some are autotrophs, others are heterotrophs
* some have a cell wall made of cellulose
* most diverse kingdom
* most profilic examples are paramecia and rotifers
* common protists
* euglena sp.
* amoeba sp. - eats everything they stick to
* paramecium sp. - not very harmful
* volvox sp. - not very harmful

Kingdom Fungi

* most are multicellular (yeast - unicellular)
* heterotrophic
* includes yeast (unicellular), molds, mildews, and __mushrooms__
* cell wall made of CHITIN
* cheese molds and yeast are edible
* athlete’s foot - fungi lives in the foots’ pores

Kingdom Plantae

* multicellular
* autotrophic
* some are predatory
* most live on land
* cell wall made of CELLLOSE

Kingdom Animalia

* multicellular
* eukaryotic
* heterotrophic
* only few can photosynthesize
* live in diverse environments
* CHITIN can be found in insect’s skin