Warm Up

 How many domains are there?

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

 What are they? (try your best here)

Kingdoms and Domains

The Tree of Life Evolves

• Five Kingdoms – Scientists realized there were enough differences among organisms to make 5 kingdoms: – Monera – Protista – Fungi – Plantae – Animalia

The new Kingdom

•

Six Kingdoms

–Recently, biologists recognized that Monera were composed of two distinct groups: Eubacteria and Archaebacteria.

Changing Number of Kingdoms

Introduced 1700

’

s Late 1800

’

s 1950

’

s 1990

’

s Protista Monera Eubacteria Archae bacteria Names of Kingdoms Plantae Protista Protista Plantae Fungi Fungi Plantae Plantae Animalia Animalia Animalia Animalia

The Three-Domain System

 The Three -Domain System –Molecular analyses have given rise to a new taxonomic category that is now recognized by many scientists. –The domain is a more inclusive category than any other— larger a kingdom.

than

The Three-Domain System

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

–Bacteria , which corresponds to the kingdom Eubacteria .

–Archaea , which corresponds to the kingdom Archaebacteria .

Domain Bacteria

 Domain Bacteria = Eubacteria Kingdom – Members of the domain Bacteria are unicellular prokaryotes .

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

that surround – Their cell walls contain peptidoglycan. – Autotrophs or Heterotrophs – Ex. Streptococcus, Escherichia. Coli

Domain Archaea

 The domain Archaea corresponds to the kingdom Archaebacteria .

– are unicellular prokaryotes . – They live in extreme environments.

– Their cell walls other organism. lack peptidoglycan, and their cell membranes contain unusual lipids not found in any – Autotrophs or heterotrophs – Ex. Methogens and Helophiles

Domain 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 Protista

• composed of eukaryotic organisms that cannot be classified as animals, plants , or fungi .

– Its members display the greatest variety.

– They can be unicellular or multicellular – photosynthetic or heterotrophic – and can share characteristics animals.

with plants, fungi, or – Ex. Amoeba, Paramecium, slime molds, giant kelp

paramecium Volvox Amoeba Slime Mold

Kingdom Fungi

• • Eukaryotic Are heterotrophs -Most fungi feed on dead or decaying organic matter by secreting digestive enzymes into it and absorbing small food molecules into their bodies. – They can be either multicellular or unicellular – Cell walls made of chitin – Ex. Mushrooms, yeast

Kingdom Fungi

Kingdom Plantae

• • • • • • Eukaryotic Multicellular photosynthetic autotrophs chloroplasts – contains nonmotile —they cannot move from place to place. cell walls that contain cellulose . Ex. includes cone-bearing and flowering plants as well as mosses and ferns.

Kingdom Animalia

• • multicellular heterotrophic.

– The cells of animals do not have cell walls. – Most animals can move about. – There is great diversity within the animal kingdom, and many species exist in nearly every part of the planet.

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

What Is a Virus?



Viruses

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

reproduce only

infecting living cells . by   Viruses differ widely in terms of size and structure. All viruses enter living cells and use the infected cell to produce more viruses.

.

Viruses and Living Cells

 Viruses must grow and infect reproduce.

a living cell in order to  They take advantage respiration, nutrition, and all other functions of living things.

of the host ’ s  Viruses have many of the characteristics of living things.  After infecting living cells, viruses can reproduce, regulate gene expression, and even evolve.

Viruses and Living Cells

 Because viruses are dependent things, it seems likely that viruses developed after living cells . on living  The first viruses may have evolved from genetic material of living cells.  Viruses have continued to evolve over billions of years.

Viruses vs Living Cells

Characteristics Structure Reproduction Genetic Code Growth and Development Obtain and use energy No No Response to environment Change over time Virus DNA or RNA core, capsid Only with in host cell DNA or RNA No Yes Cells Cell membrane, cytoplasm, nucleus and organelles Asexually or sexually DNA yes yes yes yes