Biological Diversity BSCI 10110 1 MWRF 1 10 2 00 Dr Mark Kershner Week 5 9 28 Archaebacteria Extremophiles extreme heat thermophiles extreme pH low pH acidophiles extreme salinity halophiles Methanogens Normal use H2 to reduce CO2 to CH4 methane find them wherever you find bacteria ubiquitous everywhere Domain Eukarya approximately 1 5 billion years old based on limited fossil record however prokaryotes were dominant for preceding approximate 2 5 billion years likely came out of endosymbiotic interaction one prokaryotic cell engulfed another cell all multicellular except for Protista some Fungi all reproduce sexually to some degree compartmentalization allows for cellular specialization allows different types of cells to develop into different tissue Kingdom Animalia multicellular heterotrophs most have a nervous system complex tissues motile can move Kingdom Plantae Viridiplantae consuming ingesting organic matter produced by other organisms green plants autotrophs produce own energy photosynthesis complex tissues cell walls made of cellulose Kingdom Fungi multicellular unicellular heterotrophs absorption cell walls made of chitin Kingdom Protista multicellular unicellular autotrophs heterotrophs or both some have cell walls of varying composition have lineages with fungal animal plant characteristics or are very different Fig 26 9 Endosymbiosis ancestral eukaryotic cell was a unicellular protest ancestral eukaryotic cell engulfs aerobic bacterium energy producing organisms becoming an energy producer eukaryotic cell with mitochondrion engulfs a photosynthetic bacterium becoming and energy harvester eukaryotic cell with chloroplast and mitochondrion split to non photosynthetic and photosynthetic bacteria engulfed and introduced in membrane aerobic bacterium most likely the purple non sulfur bacteria photosynthetic bacterium most likely cyanobacteria 9 30 Endosybiotic Theory phagocytosis in a eukaryotic cell engulfs bacteria cell and usually enzymes break down introduced to survive must be double membraned by vacuole Hataena protest Nephroselmis alga symbiosis mitochondrion and chloroplasts all have double membranes would need to pass them to subsequent generations binary fission produces two identical daughter cells or a daughter cell with and one without mitochondrion chloroplast are capable of autonomous division expectation have own genetic material mitochondrions chloroplast possess small circular chromosomes ribosomes similar to bacteria at some point they must have started to produce some benefit for the cell chloroplast built in energy harvesters cyanobacteria mitochondrion energy producers purple sulfur bacteria mitochondrion chloroplast genetic material matches up with cyanobacteria and purple sulfur bacteria Viruses Chapter 27 not clearly living not cellular a bag of protein filled with genetic material cannot reproduce on own require hosts parasitic chemicals all living things have viruses each virus has a limited host range target specific tissues tissue tropism highly variable in size shape structure evolve rapidly Virus genetic element encased in protein capsid DNA RNA nucleic acids single double stranded forms circular or linear forms Fig 27 1 Helical capsid helix shaped RNA plant virus TMV Icosahedral capsid often found as a virus affecting mucus membranes genetic element enclosed in capsid projected proteins animal virus Adenovirus Icosahedral head helical tail bacterial virus bacteriophage Helical capsid within envelope genetic element within capsid animal virus influenza 10 1 all viruses have a genetic element found inside a protein coat capsid some like influenza have a capsid within an envelope envelope composed of proteins and lipids tissue recognition viruses possess their own genomes associated with reproduction and replication must use host machinery for DNA RNA replication Bacteriophage Fig 27 3 virus infects bacteria 0 05um 1um 1 1millionth of a meter Fig 27 5 Lytic cycle produced viral Attachment Lysogenic cycle Vibrio cholerae cholera bacterium phage conversion Antigen shift influenza virulent stage lysis cell rupture Attachment Penetration tail push it through cell wall inject DNA Synthesis viral genes take over the cell Assembly DNA viral pieces and parts Release virion lysogeny integration of viral genome into host genome does not kill cell Integration Propagation Induction prophage union of two genomes exits the chromosome Lytic cycle Vibrio cholerae when uninfected harmless Vibrio cholerae is infected by a bacteriophage bacteriophage introduces a gene that codes for cholera toxin diseases affected by phage conversion Diphtheria some strains of Salmonella H antigen N antigen hemagglutin getting into recognizing host cells neuraminidase getting out of host cells H proteins have a very high mutation rate genes for H can recombine between strains within hosts jumps hosts change transmission pathways allow escape from antibodies Flu viruses RNA viruses virus replication is error prone high mutation rates tough targets HIV DNA viruses significantly lower mutation rates fewer errors during replication poxes hepatitis B herpes 10 2 DNA viruses vs RNA viruses RNA more error prone during replication RNA viruses changes are associated with H and N antigens DNA viruses poxes Flu viruses H getting in N getting out Bird flu A H5N1 Avian bird flu poultry wild birds human between birds and humans host jump no jump between humans and humans H1N1 virus Vaccines are problematic trying to hit a moving target usually target H antigens HIV RNA virus retrovirus copies itself into DNA before entering host Ex structure and reproductive cycle of HIV White blood cells alters immune system function AIDS Acquired Immune Deficiency Syndrome AZT numbers for virus name related to morphology shape order reduces viral replication protease inhibitors PIs alters capsid formation combo treatment AZT and PIs HIV vaccine Australian chap variable resistance to HIV SARS Hantavirus Ebola receptor mutation that prevented viral bonding
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