Classification The evolution of Complexity: single cell prokaryote to multicellular eukaryotes

Aristotle to Linneaus Taxonomy- classifying organisms Binomial nomenclature and scientific names Canis lupus, Turdis migratoris, Felis catus Systematics- the study of biodiversity and its classification, create phylogenies Phylogeny- an organism’s evolutionary history, a phylogenetic tree

Modern Classification System DomainArchea, Eubacteria, and Eukarya KingdomArcheabacteria, Eubacteria, Protista, Fungi, Plant, Animal Phylum Class Order Family GenusFirst part of Scientific name Species Second part of Scientific name

The Evolution of Complexity Earth is approximately 4.5 billion years old 1 st living things, prokaryotic bacteria cells are found in the fossil record dating 3.5 billion years ago 1 st eukaryotic cells appear in fossil record dating 2.1 billion years ago Between million years ago the fossil record shows the diversity of algae and small animal like organisms

Origin of Life Spontaneous Generation: life from non-life was replaced with – Biogenesis Oparin’s hypothesis of the origin of life was tested by Miller and Urey, creating organic compounds but not life Endosymbiosis- the hypothesis behind the evolution of eukaryotes from prokaryotes

What is a Virus?- nonliving… Composed of genetic material, RNA or DNA, and a protein coat Genetic material surrounded by a protein coat, must have a host cell in order to reproduce Life cycles: Lytic (kills host cell) or Lysogenic (incorporates DNA into host)

Human viral diseases Virus- disease Flavivirus- Yellow Fever HIV- AIDS Herpes virus 3- Chicken pox Filovirus- Ebola Hepatitus B- Hepatitus Influenza virus- Influenza or pneumonia Epstien- Barr virus- Mono Polio virus- Polio Rhabdovirus- Rabies Voriola virus- Smallpox Paramyxovirus- Mumps

3 Domains 1.Archea 2.Eubacteria 3.Eukarya Bacteria once belonged to the same Kingdom, Monera, but through Molecular Biology and the study of evolution, Biologist realized they had critical differences and should be placed into their own category so the “Domain” classification level was created.

6 Kingdoms

Archea and Eubacteria Archea Kingdom All prokaryotic single celled organisms. No Peptidoglycan in cell wall Most ancient and extreme They live in the harshest environments Methanogens (anaerobic), thermoacidophiles (hot) and halophiles (salty) Eubacteria Kingdom True bacteria, all prokaryotic single celled Have Peptidoglycan in cell wall Classified by their shape and gram staining Gram + have more peptidoglycan and stain purple Gram – have less peptidoglycan and stain pink

Shapes and Examples Sphere- Cocci, can occur in chains Streptococcus Pneumoniae which can cause strep throat or Scarlet fever, or grapelike clusters Staphylococcus aureus which can cause skin infections and Toxic Shock syndrome Rod- Bacillus ex Escherichia coli (E.coli), Lactobacilli which can cause tooth decay or one strain makes Sourdough bread, other bacilli can cause botulism, typhoid fever, and anthrax Spiral- Spirilla comes in 3 shapes 1. Vibro which is curved caused Cholera, 2. Spirillum (thick spiral), and 3. Spirochete (thin spiral) ex. Treponema pallidum causes Syphilis and another strain can cause Lyme disease

Essential Bacteria: ecosystems depend on these small organisms Cyanobacteria- photosynthetic/producers, building blocks of most aquatic food webs Nitrogen- Fixing Bacteria- symbiotic relationship with plants, they help them absorb nitrogen from the soil. Helpful: fermentation, digestion, biotechnology, nitrogen fixing, decomposers, oxygen producers Antibiotics kill bacteria by destroying the cell wall, gram negative have an extra lipid layer that prevents the antibiotics from entering the cell.

Reproduction Bacteria reproduce asexually, binary fission Each bacteria has a single chromosome but can have additional DNA in the form of plasmids. Plasmids increase Bacterial genetic variation and contribute to Bacteria evolution Plasmids can be exchanged between different bacteria (even different species) by a process called conjugation. Plasmids can also be taken up by bacteria from their environment via transformation. Additional DNA recombination can be introduced via a bacteriophage, this is called transduction.

Review of Bacteria All bacteria: Reproduce asexually Single celled Have cell wall Single strand of DNA Some Bacteria: Autotrophic Heterotrophic Some move by flagella, slime, spiral motion Some produce endospores which allow them to go dormant during hostile conditions Some produce toxins