Unit 6 – Lecture 1

Recall Classification Organisms are classified by: cell type body type how they attain nutrition genetic composition

Domains There are three domains of Life: Bacteria Archaea Eukarya

Domain: Bacteria Kingdom Eubacteria prokaryotic unicellular

Domain: Bacteria Kingdom Eubacteria asexual reproduction sometimes with conjugation using pili [sing = pilus]

Domain: Bacteria Kingdom Eubacteria strong cell wall can be autotroph or heterotroph saphrophyte parasite chemoautotroph photoautotroph

Domain: Bacteria Kingdom Eubacteria found almost everywhere except for extreme environments some have locomotion flagella cilia

Domain: Bacteria Kingdom Eubacteria three basic body shapes: bacillus coccus spirillum strep = chains staph = clusters

Domain: Archaea Kingdom Archaebacteria prokaryotic unicellular asexual reproduction sometimes with conjugation

Domain: Archaea Kingdom Archaebacteria strong cell wall with unique composition autotrophic photoautotroph chemoautotroph

Domain: Archaea Kingdom Archaebacteria closer genetically to eukaryotes than eubacteria live in extreme environments high heat, high salt

Domain: Eukarya Kingdoms Protista, Fungi, Animalia, Plantae very diverse but all are eukaryotic unicellular or multicellular highly organized sexual or asexual reproduction

Recall – Characteristics of Life organized into cells reproduces can pass traits to offspring grows/develops needs energy maintains homeostasis responds to stimuli

Viruses Living or not? Up for debate. Multiple forms: helix icosahedral bacteriophage and more

Viruses Bacteriophage anatomy capsid [head] neck nucleic acid tail / sheath tail fibers

Viruses Reproduction must occur in a host cell two cycles: lytic cycle lysogenic cycle

Viruses Lytic Cycle infection DNA is incorporated viral DNA uses host to replicate DNA and make more viruses destruction

Viruses Lysogenic Cycle infection incorporation of DNA DNA is dormant & replicates with cell info during cell cycle

Viruses Prion – “evil misshapen protein” responsible for mad cow disease which destroys brain tissue recent discoveries, however, show that “normal” prions may have an important role in keeping nerve cells healthy

Viruses Uses for viruses vaccines gene therapy

Recall – Characteristics of Life organized into cells reproduces can pass traits to offspring grows/develops needs energy maintains homeostasis responds to stimuli