Warm UpWarm Up

How many domains are there?How many domains are there? What are they (try your best here)What are they (try your best here) How many kingdoms do you think How many kingdoms do you think

there are?there are? What are they? (try your best here)What are they? (try your best here)

Kingdoms and DomainsKingdoms and Domains

The Tree of Life EvolvesThe Tree of Life Evolves

• FiveFive Kingdoms Kingdoms– Scientists realized there were enough Scientists realized there were enough

differences among organisms to make 5 differences among organisms to make 5 kingdoms:kingdoms:–Monera–Protista–Fungi–Plantae–Animalia

The new KingdomThe new Kingdom

•Six KingdomsSix Kingdoms–Recently, biologists recognized Recently, biologists recognized that that MoneraMonera were composed of were composed of two distinct groups: distinct groups: Eubacteria and and Archaebacteria.

Changing Number of Kingdoms

Introduced Names of Kingdoms

1700’s

Late 1800’s

1950’s

1990’s

Plantae Animalia

Protista Plantae

Monera Protista Fungi Plantae

Eubacteria Archae-bacteria

Animalia

Animalia

AnimaliaProtista Fungi Plantae

The Three-Domain SystemThe Three-Domain System

The The Three-Domain System-Domain System–Molecular analyses have given Molecular analyses have given rise to a new taxonomic rise to a new taxonomic category that is now category that is now recognized by many scientists. recognized by many scientists.

–The The domain is a more inclusive is a more inclusive category than any other—category than any other—larger than a than a kingdom.

The Three-Domain SystemThe Three-Domain System

•The three domains are:–Eukarya, which is composed of protists, fungi, plants, and animals.

–BacteriaBacteria, which corresponds to the kingdom Eubacteria.

–Archaea, which corresponds to the kingdom Archaebacteria.

Domain BacteriaDomain Bacteria

Domain Domain BacteriaBacteria = = EubacteriaEubacteria KingdomKingdom

– Members of the domain Bacteria are Members of the domain Bacteria are unicellular prokaryotesunicellular prokaryotes..

– Their cells have Their cells have thick, rigid cell wallsthick, rigid cell walls that that surround a cell membrane.surround a cell membrane.

– Their Their cell wallscell walls contain peptidoglycan. contain peptidoglycan. – AutotrophsAutotrophs or or HeterotrophsHeterotrophs– Ex. Ex. Streptococcus, Escherichia. ColiStreptococcus, Escherichia. Coli

Domain ArchaeaDomain Archaea

The domain The domain ArchaeaArchaea corresponds corresponds to the kingdom to the kingdom ArchaebacteriaArchaebacteria..

– are are unicellularunicellular prokaryotesprokaryotes. . – They live in They live in extremeextreme environments. environments.– Their cell walls Their cell walls lack lack peptidoglycan, and peptidoglycan, and

their cell membranes contain unusual their cell membranes contain unusual lipids not found in any other organism. lipids not found in any other organism.

– AutotrophsAutotrophs or or heterotrophsheterotrophs– Ex. Methogens and HelophilesEx. Methogens and Helophiles

Domain EukaryaDomain Eukarya

Domain Eukarya– The domain Eukarya consists of

organisms that have a nucleus.– This domain is organized into four

kingdoms: – Protista– Fungi– Plantae– Animalia

Kingdom ProtistaKingdom Protista

• composed of composed of eukaryotic eukaryotic organisms organisms that cannot be that cannot be classifiedclassified asas animals, s, plantsplants, or , or fungifungi..– Its members display the Its members display the greatestgreatest variety. variety.– They can be They can be unicellular or or multicellularmulticellular– photosynthetic or or heterotrophicheterotrophic– and can and can share characteristicscharacteristics with with plants, plants,

fungi, or animals.fungi, or animals.– Ex. Amoeba, Paramecium, slime molds, Ex. Amoeba, Paramecium, slime molds,

giant kelpgiant kelp

Slime MoldAmoeba

paramecium

Volvox

Kingdom FungiKingdom Fungi

• EukaryoticEukaryotic• Are Are heterotrophs -Most fungi feed on -Most fungi feed on

dead or decaying organic matter by dead or decaying organic matter by secreting digestive enzymes into it and secreting digestive enzymes into it and absorbing small food molecules into absorbing small food molecules into their bodies. their bodies. – They can be either They can be either multicellularmulticellular or or

unicellular unicellular – Cell walls made of Cell walls made of chitinchitin– Ex. Mushrooms, yeastEx. Mushrooms, yeast

Kingdom FungiKingdom Fungi

Kingdom PlantaeKingdom Plantae

• Eukaryotic • Multicellular• photosynthetic photosynthetic autotrophs – contains – contains

chloroplastschloroplasts• nonmotile—they cannot move from —they cannot move from

place to place. place to place. • cell walls that contain cell walls that contain cellulose. . • Ex. includes cone-bearing and Ex. includes cone-bearing and

flowering plants as well as mosses and flowering plants as well as mosses and ferns.ferns.

Kingdom AnimaliaKingdom Animalia

• multicellular • heterotrophic.

– The cells of animals do The cells of animals do not have cell have cell walls. walls.

– Most animals Most animals can move about. move about. – There is great There is great diversity within the animal within the animal

kingdom, and many species exist in kingdom, and many species exist in nearly nearly every part of the planet. part of the planet.

– Ex. Humans, birds, worms, Insects, fish, Ex. Humans, birds, worms, Insects, fish, mammals, Clams, Lobsters, Spongesmammals, Clams, Lobsters, Sponges

What Is a Virus?What Is a Virus?

Viruses are particles of nucleic acid, protein, and in some cases, lipids.

Viruses can reproduce only by infecting living cells.

Viruses differ widely in terms of size and Viruses differ widely in terms of size and structure. structure.

All viruses All viruses enter living cells and use the living cells and use the infected cell to produce infected cell to produce more viruses. viruses.

.

Viruses and Living CellsViruses and Living Cells

Viruses must infect a living cell in order to grow and reproduce.

They take advantage of the host’s respiration, nutrition, and all other functions of living things.

Viruses have many of the characteristics of Viruses have many of the characteristics of living things. living things.

After infecting living cells, viruses can After infecting living cells, viruses can reproduce, regulate gene expression, and reproduce, regulate gene expression, and even evolve. even evolve.

Viruses and Living CellsViruses and Living Cells

Because viruses are Because viruses are dependent on on living things, it seems likely that living things, it seems likely that viruses developed after living viruses developed after living cells. .

The first viruses may have The first viruses may have evolved from genetic material of living cells. from genetic material of living cells.

Viruses have continued to evolve Viruses have continued to evolve over billions of years.over billions of years.

Viruses vs Living CellsViruses vs Living Cells

CharacteristiCharacteristicscs

VirusVirus CellsCells

StructureStructure DNA or RNA core, DNA or RNA core, capsidcapsid

Cell membrane, Cell membrane, cytoplasm, nucleus cytoplasm, nucleus and organellesand organelles

ReproductionReproduction Only with in host Only with in host cellcell

Asexually or Asexually or sexuallysexually

Genetic CodeGenetic Code DNA or RNADNA or RNA DNADNAGrowth and Growth and DevelopmentDevelopment

NoNo yesyes

Obtain and use Obtain and use energyenergy

NoNo yesyes

Response to Response to environmentenvironment

NoNo yesyes

Change over timeChange over time YesYes yesyes