Exam 2 Review Types of Evolution 02 26 2014 Monophyletic An organism is grouped with all of its descendants Paraphyletic An organism is grouped with some of its descendants o Mammals o Fish Polyphyletic A group of organisms don t share a common ancestor Protists Eukaryotic Membrane bound organelles Any organism that is not a plant animal or fungus Mostly unicellular lacking specialized tissue if multicellular Paraphyletic Original historical classifications of life based on observable characteristics behavior appearance o DNA sequencing reclassified based on genetics Many are relevent o Parasites Giardia Trychomonas Trypanosoma o Termites enzyme producing motility for protists o Algae Oxygen production photosynthetic 70 80 of world s oxygen produces by algae Biofuels oil in algae to produce fuel Consumes CO2 from environment Waste for fertilizer feedstock Kingdom Alveolata Monophyletic characterized by alveolae o Dinoflagellates 2 unequal flagella Unicellular aquatic complex membranes Can be photosynthetic mixotrophic or heterotrophic 90 marine plankton Bioluminescence light produced from biological pathways scintillons Burglar hypothesis Coral reefs mutualistic Provide products of photosynthesis mediate nutrient transfer and enhance calcification Receive protection and CO2 Reefs are actually white algae give color Bleaching results from loss of algae or loss of photosynthetic pigments Storms water temperature change acid Reefs are billion dollar industry Few dinoflagellates produce neurotoxins Defensive and offensive Algal blooms can result o Increasing frequency and intensity o Cause dead zones No O2 Neurotoxins Saxitoxins Brevetoxins Ciguatoxins o Apicomplexans Infect cells using apical complex Cluster of microtubules at apex Complicated lifecycles with many hosts Plasmodium Malaria Steril Insect Technique Genetically Engineer Taxoplasma Gondii Intestine of cats Can infect any warm blooded creature Estimated 50 of world is infected Requires intermediate host Rats Mice Delayed reaction time of infected Linked to Schizophrenia Kingdom Stramenopila Characterized by hair like projections o Stramen flagellum Pilos hair o Diatoms Most abundant photosynthetic organism in oceans Inorganic cell wall made largely of silica Lack flagella non motile Very sensitive to water chemistry Pest control filtration abrasion absorption agriculture o Golden Algae Mostly freshwater Mixotrophic Prey using pseudopodia actin Produce toxins to gill breathing fish o Brown Algae Largest of all protists Seaweeds and kelp Fertilizer animal feed medicinal food o Oomycetes Molds and mildews Originally characterized as fungi absorb Look like hyphae Cell wall is cellulose not chitin fungi Cells are diploid not fungi Nutrient cycling can be parasitic pathogenic Potato Famine 1845 Kingdom Rhodophyta Red Algae Phycobilin o Seaweeds lack flagella o Important for corals human diets products Kingdom Chlorophyta Green Algae o Most similar to plants store as starch o Alternate generations are haploid o Slime Molds Intelligent External memory With modified mitochondria o Diplomads Have mitosomes Cannot carry out cellular respiration Lack ETCs Get energy from glycolysis Anaerobic environments ie Gardia o Parabasalids Have hydrogenosomes Flagella common Also anaerobic environments Symbioses An extended and close association between two species Host larger and microsymbiont smaller Mutualism o Nitrogen fixing bacteria bacteria provide plants with nitrogen plants provide bacteria with carbon fix CO2 Commensalism 0 Parasitic o Cattle Egret Movement of cattle stirs up insects birds eat o Salmonella Chlamydia Fleas Ticks Tapeworms o Exotoxins Proteins secreted by prokaryotes o Endotoxins Surface protein components of the outer cell membrane of some gram negative bacteria Never static always changing o Opportunistic infection normally communalistic becomes pathogenic in response to a changed environment Ie Weakened immune system Humans and Bacteria Over 100 trillion bacterial cells in on our body Mutualism Ferment carbohydrates aid in mineral absorption produce vitamins immunity prevention of allergies Human Microbiome Project 2007 large variation Natural Selection o Varies by region diet antibiotic exposure form of delivery o Implication Obesity allergies Crohn s infection clearing Rapid cell division quickly increasing variation within populations Food Production Yogurts cheeses wine fermentation Medicinal Insulin clotting factors growth hormone Bioremediation Organisms can remove neutralize pollutants oil Random genetic variation can be 0 or Selective pressures keep or eliminate variations o Antibiotic resistance will be selected for in the presence of the antibiotic and then passed on in reproduction o Antibacterial soap BAD Variation does not occur in response to changing environments Early Earth Carbon from Methane or CO2 Nitrogen gas Metabolic Modes Where does the organism get energy to make ATP o Photo light energy to make ATP o Chemo Breakdown of carbon molecules to make ATP Where does the organism obtain carbon o Auto Fixes CO2 into solid carbon o Hetero Must get carbon from other solid carbon Only prokaryotes are photoheterotrophs and chemoautotrophs Endospores Eukaryotic Cells Thickly coated with proteins to provide protection o Used in harsh conditions o Protect from UV enzymes freezing drying temperatures Usually triggered by lack or available nutrients o Metabolically dormant Spores contain Bacterium s DNA ribosomes dipocolinic acid As conditions improve Activation Germination Outgrowth o Return to vegetative metabolically active cells o Has happened from fossils millions of years old Cell Size Volume increases faster than surface area o Need to maximize surface area to volume ratio Surface area limits rate of entrance exit More volume means more time to more across cell Need high efficiency for distributing nutrients and removing waste o Folding internal organelle membranes utilize this idea too Nucleus Where DNA is stored o Site of gene expression o Chromatin DNA packaged with proteins o Nucleolus Formed around specific chromosomal sites Can be multiple nucleoli in one nucleus Made of protein and RNA Produces proto ribosomes o Nuclear Envelope Double membrane two bilayers Helps regulate gene expression Nuclear pores Specialized proteins Regulate molecule movement into out of nucleus Outer connects to Endoplasmic Reticulum ER o Gene expression DNA copied to messenger RNA mRNA in nucleus mRNA leaves nucleus