Exam 2 ReviewBio200Lecture 12Prokaryotes Vs EukaryotesBacteria analysis before genetic analysis 1. Shape*2. Metabolism*3. Gram +/-*4. Motile or not (variable)5. Photosynthetic or not (variable)6. Unicellular, colony forming or filamentous (variable)ShapeMetabolism1. Obligate aerobes: Must have oxygen for survival2. Obligate anaerobes: Cannot survive in oxygenated environments3. Facultative anaerobes: Can switch between aerobic and anaerobic metabolism depending on whether or not oxygen is present4. Aerotolerant anaerobes: Does not require oxygenGram Positive, Gram Negative-Gram Positive: Have peptidoglycan on the exterior cell wall, stain with the gram stain-Gram Negative: No peptidoglycan on the exterior of the cell, do not stain with the gram stainMetabolism StylesAutotrophs• “Self Feeders”1. Photoautotrophs: Chlorophyll=pigment to gain energy, water=electron donor, make sugars2. Chemoautotrophs: Chemical bonds=energy source, CO2=organic material, make sugarsHeterotrophs• “Other Feeders”1. Photoheterotrophs: Bacteriochlorophyll=pigment, H2S=electron donor, cannot breakdown CO2 so they must get carbon from other organisms2. Chemoheterotrophs: get necessary nourishment from other organismsBacterial Groups (Brief Overview)1. Low GC, Gram Positive: Can be dormant for long periods of time2. High GC, Gram Positive: filamentous3. Hyperthermophilic: extreme heat lovers4. Hadobacteria: heat loving5. Cyanobacteria: critical photoautotrophs6. Spirochetes: axial filaments, common pathogens7. Chlamydias: very small, parasitic, cocci8. Proteobacteria: very diverse metabolic pathwaysArchaea Groups1. Crenarchaeota: many love hot, cold or acidic environments2. Euryarchaeota: methanogens, halophiles, and extreme thermophilesLecture 13Eukaryotic Cell• Events that preceded the origin of the eukaryotic cell:1. Flexible cell surface2. Cytoskeleton3. Nuclear envelope4. Digestive Vacuoles5. EndosymbiosisEukaryotic Traits1. Multicellularity2. Cytoskeleton3. Compartmentalization: several stagesa) Loss of cell wall:b) Endosymbiosis with proteobacteria:c) Endosymbiosis with cyanobacteria:Protist Variation• Highly paraphyletic1. Locomotion: flagella, cilia, pseudopodia2. Cell surfaces: highly variable3. Nutrition: highly variable4. Reproduction: highly variable*Variation in all of these traits bring up issues with traditional classificationsProtist Breakdown• SAR1) Alveolates: presence of alveolia) Apicomplexians: parasites with apical complexesb) Dianoflagellates: photosynthetic, have 2 flagella within 2 grooves on their surfacec) Ciliates: heterotrophic, move using cilia2) Stramenophiles: fine hairs extending from their flagellaa) Brown Algae: photosynthetic, multicellularb) Diatoms: often photosynthetic, excrete protective silica shellsc) Oomycetes: not molds, used external digestion3) Rhizaria: unicellular, aquatica) Foraminiferans: fossilize easilyProtist Breakdown• Excavates: very diverse1) Diplomonads: parabasalids, no mitochondria 2) Euglenids: heterotrophs or autotrophs• Amoebozoans:1) Loboseans: move using pseudopodia2) Plasmodial Slime Molds: can be asexual as long as there is enough food, have vegetative and sexual stages3) Cellular Slime Molds: same as aboveProtist Breakdown• Opisthokonts: 1) Choanoflagellates: ancestral to animals2) Animals:3) Fungi:Lecture 14Land PlantsProblems to overcome• Drying out• Structural support• ReproductionAdaptations• Embryophytic• Cuticle• Stomata• Pigmentation• Fungal relationships• Tracheid cells• Thick spore walls• SeedsDiplontic Life CycleHaplodiplontic Life CycleGametophyticSporophyticSyngamyPlant PhylogenyPlant Phylogeny• Outgroup➢ Rhodophyta (Red Algae): multiple pigments, vary in size• Green Plants:➢ Chlorophytes: green algae• Streptophytes:➢ Stoneworts: branched apical growthNon-vascular land plants• Liverworts• Bryophytes (mosses): embryophytic, gametophyte dominant, sporophyte dependent on gametophyte, need water for sexual reproduction• HornwortsSeedless vascular plants (Tracheophytes)• Lycophytes: club mosses• Monilophytes: monophyletic➢ Horsetails: photosynthetic stems, no leaves➢ Ferns: sori enclosed sporangia1. Embryophytic2. Sporophyte dominant3. Free-living gametophyte4. Can get very largeSystem of Transport• Xylem: water and minerals up• Phloem: sugar and nutrients downLecture 15Benefits of Seeds• Embryophytic• Dispersal• DormancyHomosporous vs HeterosporousImportant Facts about seed plants• All heterosporous• Allow for dispersal• Allow for dormancy• Dramatic reduction of gametophytic phase• Sporophyte dominantGymnosperm groups• Cycads: palmlike, large and compound leaves• Ginkgos: 1 extant species, does not bear fruit➢ Dioecious: separate male and female individuals• Gnetophytes: have wood with vessels• Conifers: cone-bearing, woody seed plantsGymnosperm Terminology• Megasporangium (Nucellus): produces megaspores• Megaspore: haploid spore that produces a female gametophyte• Integument: layer of tissue around the ovule, becomes the seed coat• Seed Coat:protective tissue around a seed• Microphyle: opening in an ovule through which pollen grows to reach female gametophyteAngiosperm Terminology• Sepals• Petals• Anthers• Filaments• Stamens• Ovary• Ovules• Style• Stigma• CarpelAngiosperm Life Cycle• Male gametophytes:– Generative cell: produced by division of microspores– Sperm cell: 2 sperm cells are produced from division of the generative cell– Tube cell: produced by division of mircospores• Female gametophytes:– Egg:– Synergids: two cells accompanying the egg at one end of the megagametophyte– Antipodals: 3 haploid cells situated opposite the micropyle– Polar bodies: 2 nuclei in the central cell of megagametophyte, give rise to endosperm after fertilizationAngiosperms differ from gymnosperms• Flowers:• Reduced cell number in gametophytes:• Speed of pollen tube growth:• Double fertilization:• Triploid endosperm:• Fruit:Lectures 16-19ReviewAngiosperms• Darwin’s abominable mystery• Explains diversity of flowersArchaefructusFirst known flower– had fruit, male and female reproductive parts, no petals or sepalsAngiosperm Groups• Magnoliidae• Trimerous• Eudicots• Broad leaves with branched veins• Monocots• Thin leaves with parallel veins• TrimerousPollination• Abiotic• Water, wind• Biotic• Insects, birds, bats• Flowers wants to give and get pollen, and make
View Full Document
Unlocking...