PLANT BIO EXAM 4LECTURE 16 OBJECTIVES – FUNGICHARACTERISTICS OF FUNGIEUKARYOTIC CELLSMULTICELLULAR FILAMENTOUSHYPHAE – fungal filamentsMYCELIUM – mass of hyphaeCHITIN – in their cell wallsHETEROTROPHS – absorb organic compounds*AS SYMBIONTS- live with one another PARASITES- live in another organism & use its resources OR DETRITOVORES – absorb nutrient from decaying organismsNOT photosyntheticNO MOTILE CELLSZYGOTIC MEIOSIS PLANT PATHOGENS – host interactions & selective pressures during co-evolutionATTACK A SPECIFIC PLANT PARTBLIGHTS : areas of browning & deathWILTS: caused by blocking of vascular tissueDEVELOPMENTAL REPROGRAMMING5000+ SPECIES OF FUNGI ATTACK VALUABLE CROPS & GARDEN PLANTS EX. RUSTS & SMUTS – billions of $$ of damage each yearIRISH POTATO FAMINE SERIOUS DISEASES IN ANIMALS & HUMANSEX. pneumonia, ringworm, athletes footYEAST PRODUCE ETHANOL & CARBON DIOXIDE – central role in baking, brewing, wineDISTINCTIVE FLAVORS IN CHEESESIMPORTANT PHARMACEUTICALSPENICILLIN – 1st widely used antibioticCYCLOSPORIN – suppresses immune reaction organ transplants3 GROUPS OF FUNGIZYGOMYCETESFORMATION OF SPORES WITHIN ZYGOSPRANGIUMBODY OF STOLONS (connect sporangiophore) & RHIZOIDSASEXUAL REPRODUCTION – SPORANGIA & SPORESGAMETANGIA (N) – multinucleate, result of cell fusion before zygosporangiumZYGOSPORANGIUM – cell fusion of mating type + & - sporangiums , then nuclearfusion & meiosis (haploid spores)ASCOMYCETESFORMATION OF SPORES IN ASCUSCONIDIA – multinucleate spores on ends oh hyphae do external asexual reproductionSEXUAL REPRODUCTION male nuclei from ANTHERIDIUM pass over to ASCOGONIUM via trichogyne(bridge) where cell fusion occurs, DIKARYOTIC HYPHAE(N+N)grow out of ASCOGONIUM & form multicellular fruiting body(ASCOCARP), in ascocarp layers of cells form ASCUS which undergoNUCLEAR FUSION & MEIOSIS to form haploid ASCOSPORESYEASTUNICELLULAR FUNGI –mostly ascomycetesEX. BAKERS/BREWERS YEASTBASIDIOMYCETESEX. MUSHROOMS, JELLY FUNGI, RUSTSmushrooms have cap, stalk, & gills on lower surface(spores)FORMATION OF SPORES ON BASIDIUM – sexual reproductionmost have NO asexual reproduction SEXUAL REPRODUCTION – MONOKARYOTIC HYPHAE fuse at tips & DIKARYOTICHYPHAE grow out to fruiting body (BASIDIOMA, BASIDIOCARP forms),NUCLEAR FUSION to make BASIDIA, go through MEIOSIS & BASIDIOSPORES are released SYMBIOTIC ASSOCIATIONS LICHENS BETWEEN FUNGI (usually ascomycetes) & PHOTOSYNTHETIC GREEN ALGA/CYANOBACTERIAMYCORRHIZAEBETWEEN FUNGI (certain zygomycetes & basidiomycetes) &PLANT ROOTS – maximize surface area & nutrient uptakeLECTURE 17 OBJECTIVES – PROTISTSENDOSYMBIOSIS – organism is engulfed by cell & becomes organellePRIMARY – eukaryotic organism takes up cyanobacteriaEx. red & green algae, green plantsSECONDARY – organism takes up product of primary, additional membranes onorganelles, occurred 3 different times for algal groupsEx. diatoms, dinoflagellates, brown algaePHYTOPLANKTON – tiny photosynthetic organisms suspended in the water columnIMPORTANCESBIOLOGICAL – base of the food chain in open oceansECOLOGICAL – produce about 30% of atmospheric 02RED TIDESTOXIC BLOOMS – overpopulation of dinoflagellates (produce neurotoxins)KILLS FISH & PARALYTIC SHELLFISH POISONING IN PEOPLEMEIOSIS – FROM EXAM ONEGAMETIC – animals, some protists & algaeZYGOTIC – fungi, some algae SPORIC – alternation of generations – plants, many algaeGREEN ALGAEGREEN ALGAE + LAND PLANTS = GREEN PLANTSALL THREE LIFE CYCLESMAINLY AQUATICCHLOROPHYLL A, B & CAROTENOIDS5 EVOLUTIONARY TRENDS UNICELLULAR, COLONIES, BLADES, GIANT CELLS, OR FILAMENTSFilaments land plants3 MAJOR GROUPSCHLOROPHYCEAEULVOPHYCEAE – alternation of generationsIndependent gametophytes & sporophytesCHAROPHYCEAECHLAMYDOMONUSSINGLE CELL, 2 FLAGELLA, ASEXUAL & SEXUAL REPRODUCTIONPLANTS EVOLVED ON LAND – 470 MYAISOGAMY VS OOGAMYISOGAMY –both gametes same size & smallEX. chlamydomonasOOGAMY – egg large 7 nonmotile, sperm small & motile*parent can invest more resources in the offspring(egg)EX. VolvoxDINOFLAGELLATESUNICELLULAR2 FLAGELLACELL WALL – CELLULOSE PLATESHALF PHOTOSYNTHETIC – INGEST FOOD ALSOCHOLOPHYLL A, C & CAROTENOIDSASEXUAL REPRODUCTION – sexual is rare (zygotic meiosis)MARINE & FRESHWATERZOOANTHELLAE – lost their wall, occur as endosymbionts in sponges jellyfish etc.,responsible for photosynthetic productivity in growth of coral reefsDIATOMSUNICELLULARNO FLAGELLA – except during sexCELL WALL – CONTAINING SILICAASEXUAL REPRODUCTION – when sexual, its gametic meiosisFRESHWATER & MARINEHETEROKONTS – pairs of flagella that differ in size & ornamentationRED ALGAEMULTICELLULAR – some unicellularNO FLAGELLATROPICAL & COLD MARINE WATERS – some in fresh watersCELL WALL – CELLULOSE + AGAR & CARRAGEENANCHLOROPHYLL A + PHYCOBILLINSSEXUAL REPRODUCTION W/ ALTERNATION OF GENERATIONSSOURCE OF AGAR – capsules, cosmetics, baked goods, gel electrophoresisCARRAGEENAN- stabilizes paints, cosmetics, & dairy products, clarifying agent in beerBROWN ALGAEMULTICELLULARCELL WALL – CELLULOSE + ALGINIC ACIDTEMPERATE & COLD MARINE WATERSCHLOROPHYLL A, C & CAROTENOIDSBODY PLAN – blade, stipe, holdfastHAVE SIEVE TUBES – transport sugarsSEXUAL REPRODUCTION – gametic meiosis, alternation of generationsSOURCE OF ALGINATES – thickening agents, colloid stabilizers in food, textile, paperLECTURE 18 – BRYOPHYTES, MOSSES & FERNSBRYOPHYTESADAPTATIONS TO DRY LANDGAMETES ARE PRODUCED IN SPECIAL ORGANS W/ PROTECTIVE CELL LAYERantheridia (sperm producing)archegonia (egg producing)ZYGOTE & EMBRYO – retention of young sporophyte in archegoniumEMBRYOPHYTES – bryophytes & vascular plantsSPORE WALL HAS DECAY & DRYING RESISTANT MATERIAL – sporopolleninPARTIAL DEVELOPMENT OF CUTICLE & STOMATESABA BIOSYNTHESIS & SIGNALING**GROW IN WET CONDITIONS – sperm NEED to swim to egg for fertilizationSTILL POORLY ADAPTED TO DRY LANDSEXUAL REPRODUCTION – alternation of generations, separate male & female plantsGAMETES FORMED ON UPRIGHT STRUCTURES (gametophores)DOMINANT GAMETOPHYTE – sporophyte develops attached to & nourishedby gametophyte EGG IS NOT RELEASED – sperm swim down neck to fertilizeSPOROPHYTE WILL PRODUCE THE SPORES (go on to make new gametophytes) MOSSES REPRODUCE ASEXUALLY – production of many buds from protonema(filamentous phase) which grows from spores*’leafy’ gametophyte will develop from bud-like structureCAPSULES – w/ operculum & peristome spores, released on
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