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BIOL 165 Final: BIOL 165 Notes for FINAL EXAM - University of Waterloo

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BIOL 165
Marcel Pinheiro

BIOL 165 Notes 3 Supergroup Chromalveolata Introduction to Chromalveolates  Groups within Chromalveolata o Hypothesized supergroup consists of two monophyletic clades:  Clade Alveolate (Phylums: Ciliophora, Apicomplexa, Dinoflagellata)  Clade Chromista (Phylums: Bacillariophyta, Chrysophyta, Phaeophyta, Oomycota) o Hypothezised that both of these clades may have had a plesiomorphic chloroplast but it was lost before diversification in many phyla o Phylum Dinoflagellata is the only photosynthetic phylum to have a tertiary chloroplast o Clade Chromista aka Heterokonta or Stramenopila  Members of this clade usually have 2 chloroplasts o Phylum Cryptophyta belongs to neither clade; likely basal to Supergroup Chromalveolata  Very important from evolutionary standpoint  Phylum Cryptophyta Diagram  Pg. 161 o Unicellular eukaryotes (algae) found in marine and fresh water environments o Most are photosynthetic and are important elements in their habitat o Group is critical to understanding the evolution of plastids through serial endosymbiosis  Between second and third membrane there is a nucleomorph  remnant of red algae symbiont  Nucleomorph is the “smoking gun” that provides definitive evidence that some chloroplasts arose through endosymbiosis o Group is very complex from genetic and cellular perspective Supergroup Chromalveolata: Clade Alveolate  Clade Alveolate o Recent group of 3 long recognized phyla  Ultrastructure studies show that all 3 groups share a system of sacs underneath their membranes called alveoli  Research is still ongoing to solve the relationship among these group  are they paraphyletic?  Include: Ciliates, dinoflagellates and apicomplexans  Phylum Ciliophora Diagram  Pg. 164 o Ciliates are the most numerous heterotrophic protist group; 12,000 species divided into 3 subphyla o Characterized by numerous small undulipodia (cilia) arranged in lines o Most species are free living in puddles, ponds, lakes, oceans, Antarctic ice, hot springs and GI tracts of mammalian herbivores  Can inhabit both clean and polluted waters o Exhibit nuclear dualism and contain 2 distinct nuclei:  1) Large polyploidy nucleus that is physiologically active with 1000s of gene copies  2) Smaller diploid micronucleus whose meiotic products are exchanged during conjugation o Cells have a cytosome (cell mouth) surrounded by oral cilia that facilitate food ingestion  Phylum Ciliophora: Paramecium Diagram  Pg. 165 BIOL 165 Notes 3 o Have 2 nuclei  Large macronucleus has 1000s of copies of each gene and acts as factory to make RNA  Small micronucleus has whose meiotic products are exchanged during conjugation o Food is captured in oral groove and passed down cytosome and cytopharynx into food vacuoles  Food vacuoles migrate around the cytoplasm to allow digestion of other contents  Contractile vacuoles are water expulsion organelles o Members undergo conjugation to exchange genetic material and divide cell contents  Phylum Apicomplexa Diagram  Pg. 166 o Consists of single-celled organisms that are endoparasites of either invertebrates or vertebrates o Have complex to very complex life cycles  Can have diphasic or triphasic life cycles  Many species produce spores to allow transfer from one host to another and there may be multiple intermediate hosts o About 5000 known species  estimated 1.2 – 10 million exist o Exhibit great variation in morphology which can depend on the life history stage o First members described by van Leeuwenhock who saw oocysts in rabbits  Life Cycle of Plasmodium vivax: Natural History of Malaria Diagram  Pg. 167 o Protozoan species that causes malaria o Triphasic life cycle involves two hosts and six stages; all stages but zygote are haploid o Humans: Asexual Phase  Sporozoites (1n) enter blood stream through mosquito bite and enter liver  In liver, they multiply asexually to produce numerous merozoites which move to blood cells  Continual reproduction and invasion leads to destruction of many RBCs  Some merozoites metamorph into cells that produce gametocytes o Mosquito: Sexual Phase  Gametocytes are transported into mosquito when it takes blood meal   Develop into male and female gametes in gut  form a zygote (2n)   Zygote metamorphs into oocyte (2n) under stomach lining  undergoes meiosis  zoites(1n)  Zoites undergo mitosis  grow into sporozoites which migrate to mosquito’s salivary gland  Phylum Dinoflagellata: Dinoflagellates o Group were previously grouped with Clade Chromista due to presence of chlorophylls a, c and xanthophylls o Superstructure studies showed that they actually belonged to Clade Alveolata  They had a different host symbiont than members of Clade Chromista  Like other alveolates, dinoflagellates have alveoli under their cell membrane o Unique characteristics of phylum  1) Flat plate-like vesicles around the outer margins of the cells  2) The nuclear membrane persists through cell division; the spindle develops outside the membrane (like Euglenids)  3) Chromosomes are very densely coiled and are condensed during interphase  4) DNA has 5-hydroxymethyluracil substituted for thymine  5) Histoproteins are not associated with the DNA  6) Nucleolus is persistant during mitosis BIOL 165 Notes 3 o Group also called Dinophyta or Pyrrophyta  Usually unicellular; some species may form colonial chains that resemble mutlicellularity  Cells have 2 flagella; one in middle (transverse) and another extending from the end  Movement of transverse flagellum causes cell to whirl on axis and move forward  Other flagellum likely steers and aids in movement  About 50% of species are photosynthetic and may have secondary or tertiary chloroplasts that come from a variety of photosynthetic organisms o Most are asexual; very rarely sexual  Zygote can form a cyst (rest stage cell) which undergoes meiosis to yield more typical cells  These cysts are common in their fossil record  Ecology of Dinoflagellates o Most living members are marine, planktonic, biflagellate unicellular organisms  Important members of photoplankton and zooplankton communities due to abundance  Ex. The heterotrophic taxa are usually the first herbivores in the food chain  Ex. Peridinium and Ceratium are very abundant primary producers in water columns o Some photosynthetic species from genus Symbodinium are endosymbionts with corals, molluscs and other organisms  called zooxanrhellae  Ex. Great Barrier Reef clam keeps shell open to allow light to reach its endosymbiont  Many act as parasites for fish and other animals  Many have trichocysts like cnidarians that explosively discharge threads when stimulates  Bioluminescence occurs in 30 marine species  luciferase enzyme acts on luciferin substrate to produce light o Large blooms of dinoflagellates produce red tides  results in millions of fish kills  Toxins of dinoflagellates accumulate in filter-feeding shellfish which are not susceptible  If these shell-fish are consumed  can cause serious illness and death in humans  Ciguatera: debilitating illness caused by eating pelagic fish with high concentrations of ciguatoxin produced by Gambierdiscus Supergroup Chromalveolata: Clade Chromista  Clade Chromista o Clade is a monophyletic group: share ultrastructure features of the flagella and plastids & biochemical traits  Many of these phyla were included in separate kingdoms; only recently united due to ultrastructure of flagella zoospores that are observed in most members  Ex. Phylum Oomycota was previously grouped in Kingdom Fungi due to hyphae-like morphology o Contains heterotrophs (protozoa and fungi) and autotrophs (algae) o Zoospores are heterokontous; with 2 flagella attached to one side and bean shaped  Both flagella have lateral appendages which can be:  Tinsel type  long  Whiplash type very short, restricted to the tip  Differences in flagella is basis for different names  Stamenopiles  straw hairs  Heterokonta  two different flagella o Algal members are called chromophytes due to presence of chlorophyll c and other accessory pigments o Phylogeny of this group is still under research  needs more clarification BIOL 165 Notes 3  Phylum Bacillariophyta: Diatoms Diagram  Pg. 172 o Have secondary chloroplast derived from red algae o Sometimes treated at class level instead of phylum o Diatoms are one of the most ecologically significant groups due to their role in global primary production and importance in food webs  Found in marine, freshwater and moist habitats where light is available o Have 3 membrane around chloroplasts and contain chlorophylls a, c, as well as xanthopylls and carotenoids o Have unique cell structure; live in glass boxes called frustules made of pure silica  Each frustule consists of two valves or thecae where surface is finely sculptured  Patterns are visible under light microscope; details only seen under scanning electron microscope  Divided into two orders based on symmetry of frustule sculpturing  Centrales (radial)  not monophyletic  Pennates (bilateral)  monophyletic o Frustules are not biodegradable; found in fossil record going back 150 mya  Some fossil genera form deposits of diatomaceous earth (up to 6 million frustules/mL)  Material is mined for use in water filters, deodorants, abrasives and paints  Presence of these deposits may indicate presence of oil or gas  Phylum Bacillariophyta: Diatom Reproduction Diagram  Pg. 173 o Diatoms are usually diploid and reproduce asexually o Asexual reproduction: Each successive generation produced from the inner valve is progressively smaller  Cells can increase slightly in volume but frustules limit expansion  Each daughter cell must secrete one new valve; usually the inner one o Sexual reproduction: Can be induced by environmental conditions or when frustules gets too small  Meiosis yields one or two gametes from each division   Gametes fuse to form zygote  grows into normal sized cell  Zygote in pennate diatoms can form resting spore called auxospore  Phylum Chrysophyta: Golden-Brown Algae o Have secondary chloroplast derived from red algae  Thus, they have typical chromophyte pigments: chrlophyll a,c, xanthophylls and carotenoids  Chrysolaminarin (B-1,3-linked glucan) is their primary storage unit o Sometimes group will be expanded to includes most other groups of chromistan algae  Based on ultrastructure, group seems to be closer to Bacillariophyta and Xanthophyta and less to Phaeophyta  Recent studies show group may include two groups differing in ultrastructure  Synurophyta o Members include unicellular, flagellated heterokonts or simple colonial algae (freshwater plankton)  Morphologically diverse in terms of colony formation  Some taxa have silica scales  Others form chitinous vase-shaped chambers (lorica) as seen in Dinobryon  Many taxa form silaceous cysts to permit overwintering o Silica scale and cysts can fossilize and occur in deposits dating back to upper Cretaceous period BIOL 165 Notes 3  Phylum Phaeophyta: Brown Algae o Includes all brown algae; which includes the largest and most morphologically complex former kingdom  Protista; no unicellular forms o Almost all members are marines; found along rocky coastlines o Range from microscopic branched filamentous forms to macroscopic parenchymatous forms o Green chlorophylls a and c are masked by accessory pigment fucoxanthin  Fucoxanthin imparts brown colour to thalli  Xanthophylls and carotenoids also modify the brown colour o Food reserves are stored as laminarin and mannitol o Their thalli often contain alginic acids that can make up 10-25% of the dry weight  Acids used commercially for their colloidal properties o Phylum is split into 3 main groups based on life cycle characteristics  1) Alteration of isomorphic generations  2) Alterations of heteromorphic generations  3) Diploid sporothallus phase that reproduces sexually by oogamy  Phylum Phaeophyta: Life Cycle of Ectocarpus Diagram  Pg. 176 o Isomorphic alteration of generations  sporothallus and gametothallus look the same  Zygote (2n)  sporothallus (2n) undergoes mitosis  unilocular meiosporangium   Sporothallus can also undergo asexual reproduction   Plurilocular sporangium (2n)  Zoospore  sporothallus  Unilocular meiosporangium undergoes meiosis in sporangium  then rounds of mitosis to produce  Male and female meiospores (1n) which grow into  male and female gametothallus (1n)   Form plurilocular gametangium (1n) which release  isogametes  undergo isogamy  zygote  Phylum Phaeophyta: Laminaria (Kelps) o Most kelps are subtidal; occur below intertidal zone not exposed at low tide o Observed at rocky coastlines of both Atlantic and Pacific  Largest genera (Macrocystis and Nereocystis) occur on Pacific Coast  called giant kelps  Form extensive submarine forests that provide habitat for many organisms o Anchored in deep water using holdfasts; top of kelps can be seen at surface of water  Phylum Phaeophyta: Life Cycle of Laminaria Diagram  Pg. 177 o Heteromorphic alteration of generations  sporothallus and gametothallus look different  Zygote (2n)  sporothallus (2n) which has fertile zone  meiosporangium   Undergoes meiosis in sporangium  meiospores (1n) that grow into  male gametothallus   Releases sperm that fertilizes egg on female gametothallus  zygote  Phylum Phaeophyta: Fucus o Found along rocky coastlines of Atlantic Ocean o Intertidal organisms  alternately exposed to air during low tide, submerged at high tide  Fucalean brown algae have adapted to harsh changing condition and have become the dominant organisms at the rocky shoreline  form carpets of algae o Fucus also contain alginic acid which is harvested commercially (aforementioned) BIOL 165 Notes 3  Phylum Phaeophyta: Life Cycle of Fucus Diagram  Pg. 180 o Unithallic life cycle  Diploid sporothallus phase that reproduces sexually by oogamy  Adult sporothallus (2n) has projection called  receptable which contain  conceptable   Conceptable undergoes meiosis  spores (1n) grow into  male gametophyte   Antheridium released sperm  fertilizes egg from oogonium of female gametophyte   Underogoes oogamy  zygote (2n) grows into  adult sporothallus  Phylum Oomycota o Was once considered to be part of lower fungi called pseudofungi  But synapomorphic characteristics of zoophores and heterkontous flagella indicate that they are part of Clade Chromista o Usually oogamous but can also undergo asexual reproduction via zoosporangia and zoospores o One order is aquatic (water molds) o Other order is terrestrial (downey mildews)  Terrestrial forms have ascomycetous fungi  Cause great damage to crops and are of economic importance o Phytophthora infestans caused the Irish potato famine  mass starvation and forced migration of humans  Phylum Oomycota: Life Cycle of Water Molds Diagram  Pg. 181 o Sexual Reproduction (Oogamy)  Somatic hypha (2n) contains  gametangia  undergoes meiosis   Antheridium releases sperm  travels through fertilization tube  fertilizes egg in oogonium   Zygote (oospore)  grows into somatic hypha o Asexual Reproduction  Somatic hypha (2n) releases  biflagellate zoospores (2n)  can enter resting stages (encysted zoospore)  grow into somatic hypha  Phylum Oomycota: Order Peronosporales – Downey Mildews o Sporangia in this group is an asexual propahule that is dispersed by the wind  Its germination produces zoospores that can start new infections o Plasmopara: causes downey mildew of grapes o Peronospora: causes tabacco blue mold  results in great loss for Ontario tobacco farmers o Phytophthora: causes Potato Blightand other serious crop diseases  fatal diseases of trees Supergroup Opisthokonta  Introduction to Opisthokonta o Well-supported monophyletic group consisting of animals, true fungi and protists o Closest relative of animal are the chanoflagellates: free-living, unicellular or colonial flagellates o Opisthokonts share two synapomorphic features that are uncommon in other eukaryotes  1) Have flat mitochondrial cristae  2) Flagellated cells have one flagellum (undilipodium) that is at the posterior end BIOL 165 Notes 3 Supergroup Opisthokonta: Fungi  What is a Fungus? o Fungi are a monophyletic group that is not closely related to plants; closer to animals o Study of fungi  mycology o Fungi are heterotrophic decomposers; VERY important  Most of the biomass produced by autotrophs is broken down by fungi and bacteria  Only some biomass if first consumed by animals o Members have diffuse body made up of fine branching hyphae  Collectively the hyphae form the mycelium  equivalent to body  Walls of hyphae are composed of chitin and cellulose o Fungi secrete exozymes onto food substrates which are digested externally then absorbed by hyphae  Many fungi store nutrients in the form of glycogen like animals o They have evolved 3 different modes of heterotrophic existence: saprobic, parasitic and mutualistic  1) Saprobes: decompose dead matter; used commercially for producing wine, beer, bread, cheese  2) Parasites: decompose living organisms and tissues  3) Mutualistic: Combinations of fungi and algae which produce lichens o More than 90% of vascular plants depend on specific mycobionts for growth in low-phosphorous soil  Fungal hyphae form external or internal associations with plant roots called mycorrhizae  Most plants require these association to grow o Phylums: Chytridiomycota, zygomycota and dikaryokycota  The Fungal Mycelium o Collectively the hyphae form the mycelium  equivalent to body o Walls of hyphae are composed of chitin and cellulose o This differs from the mycelia of pseudofungi, chytrids and eumycotan fungi  Similarities resulted from convergent evolution of independent phylogenetic lines which adapted to the job of being consumers assimilating nutrients  Phylum Chytridiomycota o Directly related to eumycotan fungi and is included in a single fungi clade o Chytrids are parasites that don’t produce assimilative hyphae; but can produce assimilative rhizoids  Simple forms are unicellular  Complex forms are coenocytic  multinucleate with branching tubular thalli o Chytrids produce uniflagellate, asexual opisthokont type zoospores which either make more asexual fungi or gametothalli  Most have a haploid dominant life cycle  Diploid stage consists of zygote which functions as both a resting spore and a meio-sporangium o Chytrids cause reductions in amphibian populations  Also parasitize algae, plant pollen and fish o Types of growth  Simpler chytrids develop entirely within host  holocarpic  Just sporangium develops outside the host  eucarpic  Some chytrids have rhizomycelium  branching coenocytic cells with many sporangia borne outside of the host and assimilative rhizoids inside the host BIOL 165 Notes 3  Phylum Chytridiomycota: Life Cycle of Chytrid – Rhizophidium Diagram  Pg. 188 o Zygote (2n) grows  sporothallus (2n, resting stage)  undergoes meiosis  zoospores (1n)  Zoospores can undergo asexual reproduction  gametothallus  zoosporangium  zoospore o Zoospores grow  male and female gametangium  release gametes  gametes fuse  zygote  Eumycotan Fungi o Eumycotan fungi (not taxanomic) includes groups that were previously treated as Kingdom Fungi but excludes Phylum Oomycota and Phylum Chytridiomycota o These fungi form spores that are very resistant to desiccation and have no flagellate cells o Are a monophyletic group that can be divided into two groups:  Phylum Zygomycota  Phylum Dikaryomycota  Subphylum Ascomycotina  Subphylum Basidiomycotina o Differences in the 3 nuclear conditions of the triangle of life in Phylum Dikaryomycota separate the phyla and subphyla o Group also includes other “groups of convenience” that are not monophyletic  Includes: conidial fungi, yeasts and lichens o 75,000 described species  numbers can go up to millions  The Whole Fungus o Eumycotan fungi have both sexual and asexual reproductive structures that differ from each other  The telomorph  sexual phase (for higher classification)  The anamorph  asexual phase (many cases, it’s the only phase known)  Anamorph structures are very distinct, teleomorphs are not  makes classification difficult o Anamorph + Telomorph = Holomorph  Fungi have two official names for the same organism  Holomorph name is same as telomorph name Fungi: Phylum Zygomycota  Phylum Zygomycota o Includes saprobes that colonize the inside of terrestrial substrates like bread, overripe fruit and poop o Few are parasitic to humans  cause disease called mucomycoses o Their hyphae are thick, non-septate and delicate; collapse in dry air  Telomorphs all look similar  Anamorphs have sporangia that are highly varied due to different dispersal mechanisms o Sexual reproduction (telomorphic phase) involves conjugation of morphologically similar gametangia to form a zygosporangium (zygote that undergoes meiosis)  Phylum Zygomycota: Life Cycle of Bread Mold Rhizopus Diagram  Pg. 193 o Anamorphic Phase  Hyphae (1n) form  mature mitosporangia (1n) that release  mitospores (1n)   Grow back into immature mitosporangia (1n)  mature mitosporangia o Teleomorphic Phase  Gametangia undergo conjugation to form  zygosporangium (2n) which undergoes meiosis  BIOL 165 Notes 3  Sporangiophore (1n) that contains  mitosporangium (1n) which releases  mitospores (1n)   Mitospores form  gametangia which undergo conjugation Fungi: Phylum Dikaryomycota  Phylum Dikaryomycota o Phylum includes true fungi with a dikaryon (1n + 1n) phase in life cycle o Hyphae are thin, resistant to desiccation, septate and branching o Contains to subphylum which share the synapmorphy of the dikaryon stage  Subphylum Ascomycotina: Dikaryon phase is short and consists of a few special cell types produced inside the ascomata (teleomorph reproductive structures)  Subphylum Basidiomycotina: Dikaryon phase can be very long, is free-living and produces basidiomata (teleomorph reproductive structures) o Phylum also include 3 “artificial” (polyphyletic) groups that include both above subphylums  Conidial Fungi: Only known in anamorph phase; produces mitospores called conidia  Yeasts: Simple ascomycetous and basidomycetous fungi  Lichens: Symbiotic organisms with a fungal mycobiont and cyanobacterial or algal phycobiont  Meiocytes of Dikaryotic Fungi Diagram  Pg. 195 o Group produces many different kinds of meiocytes o Meiocytes are the zygote cells that undergo meiosis  Only diploid cells in the life cycle  Characteristic of these cells used as basis for classification of dikaryotic fungi o Two basic types of meiocytes: ascus and basidium  Ascomycotina: Ascospores are formed by meiosis followed by mitosis  8 endogenous ascospores produced in ascus  Basidiomycotina: Dikaryotic stage occur at base  diploid stage occurs in basidium  4 exogenous basidiospores produced from basidium after meiosis  Ascomycotina: Types of Asci o The ascus is the only diploid cell in the life cycle of ascomycetes o Asci form a dikaryotic (1n + 1n) ascogenous hyphae  becomes diploid o Asci are meiocytes  undergo meiosis to yield 4 haploid nuclei  Nuclei divide mitotically to produce 8 ascospores inside the ascus (endogenous)  Some fungi may have more ascospores due to more mitotic divisions  Ascomycotina: General Life Cycle Diagram  Pg. 197 o Note: If telemorph stage is absent, fungus is classified as a Conidial Fungus of uncertain origin o Anamorph Phase  Mycelium (1n) forms  conidia (stalk)  undergoes conidium germination   Releases mitospores (1n) which grow into  mycelium o Teleomorph Phase  Mycelium (1n) undergoes plasmogamy  dikaryotic phase occurs at base in ascogenous hyphae   Many rounds of mitosis  diploid nucleus which undergo meiosis  4 haploid nuclei   Nuclei undergo 1 round of mitosis  8 endogenous ascospores in ascus  BIOL 165 Notes 3  Undergo ascospore germination  releases ascospores (1n) which grow into  mycelium  Ascomycotina: Types of Ascomata o The ascoma is the reproductive organ in which asci are produced o Ascomata can be divided into 4 types:  Cup-shaped apothecial ascoma  Flask-shaped perithecialascoma  Flask-shaped pseudothecial ascoma  Spherical cleistothecial ascoma o Some ascomycetes produce their ascomata embedded in a mess of tissue called stroma  Dutch Elm Disease: Case History of Holomorph Invader o Dutch Elm Disease is caused by the ascomycete fungus Ophiostoma ulmi (anamorph: Graphium) o Disease is carried from tree to tree via bark beetles o May have originated from the Himalayas  destroyed more than 50% of elm trees in Canada and US  Basidiomycotina: o Key feature of group is the formation of 4 exogenous basidiospores from the basidium (meiosporangium) o Unlike most ascomycetes, basiomycetes produce large teleomorph reproductive structures  basiomata o Differences in the basidium form basis for the 3 different classes in the group  Class Holobasidiomycetes: mushrooms, toadstools, shelf fungi etc  Form largest class of basidiomycetes and are easily identifiable  Class Phragmobasidiomycetes: Jelly and ear fungi  Class Teliomycetes: Rust and smut fungi o Clamp connections: Formed by secondary mycelia; result in accurate separation of dikaryotic nuclei in newly formed hyphal cell o Hyphae of Holobasidiomycetes and Phragmobasidiomycetes have dolipore septa which have a membranous cap over the pore  Basiomata of Agarics o Agarics (mushrooms and toadstools) are the dikaryotic teleomorphic reproductive organs of one group o These structures differ if the fungi has gills or pores  In the absence or presence of universal and partial veins,  In om cap shape and texture  In colour and in spore colour  Basidiomycotina: Life Cycle of Mushroom Amanita Diagram  Pg. 210 o Zygote (2n, immature basidium)  undergoes meiosis  spores grow into  mature basidium (1n)  o Releases basidiospores  primary mycelia (1n, monokaryotic) of + and – hyphal strains  o Strains of hyphae fuse  secondary mycelium (1n + 1n, dikaryotic)  grows into basidiocarp (1n + 1n)  o Basidia in the gills of the cap undergo karyogamy  produce diploid zygote (immature basidium)  Basidiomycotina: Class Teliomycetes – Smut and Rusts o Parasitic smut and rust fungi are the two most economically important groups of the Basidiomycotina o They form resting spores (teliospores) in which karyogamy occurs  stage in basidium formation BIOL 165 Notes 3 o Smuts cause major wheat and corn crop loss  Corn smut makeslarge tumor-like galls on the ears and tassles o Rusts lack dolipore septa; have coenlomycete-like spore producing phases  Can have complex life cycles involving two different hosts  Class Teliomycetes: Life Cycle of Puccina graminis Diagram  Pg. 218 o Note: Both hosts must be present for life cycle to occur o Berberis (Alternate Host - Anamorph)  Basidiospores (1n) land on upper side of leaf  form spermagonium which contains   Spermatia (1n)  land on receptive hyphae (1n) of another leaf  hyphae undergo plasmogamy   Become dikaryotic hyphae (1n+1n)  form aecium (1n+1n)  releases aeciospores (1n+1n)  o Triticum: wheat (Primary Host - Teleomorph)  Aeciospores land on wheat  form uredinial sorus  releases urediniospores (1n+1n)   Form telial sorus  release teliospores (1n+1n, resting stage)  spores undergo karyogamy   Form bicullular diploid teliospores (2n)  spores germimate and grow undergo meiosis   Form basidium which released  basidiospores  Conidial Fungi o Group of convenience o Large group of asexually producing fungi (only anamorphic stage known)  Bin for fungi whose teleomorphic stages isn’t identified o Condial fungi is not a taxonomic name and group is polyphyletic o Most are ascomycetes; some are basidiomycetes o Divided into two anamorph classes:  Coelonmycetes: Conidia are produced in a protective flask-shaped conidium  Hyphomycetes: Conidia are produced in unprotected conidiophores o Majority of fungal diseases (mycoses) of plants and animals are caused by hyphomycetous fungi  This class is also the dominant decomposers of organic matter o Produce biochemicals that range from toxins to medicines  Yeasts: A Polyphyletic Group o Group of convenience o Fungi that are unicellular or colonial; do not form hyphae o Some are ascomycetes; some are basidiomycetes  Usually only includes their anamorphic stage; some yeasts have known holomorphs o Economically important: ferment sugars, use nitrogen, resistant to antibiotics  Important in brewing, baking, wine making and human mycoses o Saccharomyces: model organism for understanding cell cycle biology  Lichens: A Polyphyletic Group o Group of convenience o Dual organisms formed from a symbiotic relationship between fungi (mycobiont) and (phycobiont)  Phycobiont can include members of cyanobacteria or green algae o Naming depends on identification of the fungal component  Fungal component: most are ascomycetes; few are basidiomycetes BIOL 165 Notes 3 o Lichens are ubiquitous and grow in extreme environments  Some can photosynthesize at -18C and survive temps as low as -198C o They are sensitive to city pollution, acid rain and are slow growing Supergroup Opisthokonta: Clade Metazoa (Animalia)  Introduction to Clade Metazoa o Includes Phylum Choanoflagellata which have cells very similar to sponge cells but lack the ECM o Kingdom Animalia previously contained all animals; was divided into two subkingdoms  Protozoa: Contains unicellular phyla  now divided into many supergroups  Metazoa: Contains multicellular phyla o Synapomorphies shared by all animals: 4 molecules in the ECM:  Collagen: long triple helix proteins that have high tensile strength  Proteoglycans: in-vivo roles  Glycoproteins: large proteins that resist compression  Integrin: Connects ECM to outside cells o ECM is very important in animal cells  Often forms scaffolding which mineralizes to forms bones, exoskeleton, shells or spicules  Plays key role in development of animals  General Life Cycle of Metazoans o Most are diploid and reproduce sexually by making gametes via meiosis  For many, gametes are released into environment and fertilization is a chance event  For some, females are diploid but males are haploid o Big differences in how zygote develops into adult o Some have both sexual and asexual modes of reproduction  Parthenogenesis: Reproduction with unfertilized egg allows for larger numbers of reproduction  Ex. In rotifers: 2n females produce 2n eggs via parthenogenesis  develop into 2n females  Meiosis yields 1n males with 1n sperm that can fertilize the egg  2n zygotes o General Life Cycle  Zygote (2n)  offspring  growth and development  adult male and female(2n)   Undergo meiosis  egg (1n) and sperm (1n)  fertilization  zygote  Coeloms and Classification o Presence of coelom is used as a high level trait to classify metazoan  Acoelomates: lack body cavity  Pseudocoelomates: have body cavity that is not lined with peritoneum  Coelomates: have body cavity that is lined with peritoneum and is of mesodermal origin o Studies show that these characteristics are not monophyletic; can’t be used for phylogenetic classification  1) Traditional pseudocoelomate, Phylum Aschelminthes is polyphyletic  2) Coelom can develop in several ways o Thus, the coelom is not a synapomorphic trait  Embryology: Origins of the Mouth o Proteosomes: Invagination of the blastula to form the gastrula creates the mouth first, anus later o Deuterosomes: The anus forms first, the mouth later BIOL 165 Notes 3 Clade Metazoa: The First Animals  The Ediacaran Fossil Fauna o Fossils of these earliest metazoans dates back 600-540 mya (late Pre-Cambian period) o Very different from any living organism today o Hypothesized that members were sessile with little tissue differentiation  Simple lifestyle may have been possible because they had no predators yet o Burgess Shale Fossil Fauna: includes animals belonging to many current phyla  Shale dates back 530 mya  The mud of the Burgess shale preserved a lot of detail of the organisms  Phylum Ctenophora o Includes organisms called comb jellies and sea wallnuts o Bilaterally sym
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