BIOL 112 1ST EditionExam # 3 Study Guide Lectures: 23 - 33Lecture 23 (October 24)Seed Plant HistoryLand plants vascular plantsprogymnospermsseed plantsseedless vascular plants dominategymnospermsgymnosperm forests dominatecycads and conifers dominateangiospermsReproductive Adaptations of Seed PlantsHeterospory and Reduced Gametophytes- seed plants are heterosporous- spores remain within sporophyte tissue and grow into male or female gametophytes- megasporesfemale gametophytes- microsporesmale gametophytes- ovule – on a sporophyll- egg is produced and fertilized in the megasporangium- pollen- pollen (microspores) – tiny male gametophyte in sporopollenin - travel in the air to the ovules (pollination)- pollen grows a pollen tube toward the egg in within the ovule, then the sperm is released fertilization occurs within the ovule conifers and angiosperms have no flagella- seed – from the fertilized ovule- seed coat, food, embryo- efficient dispersal enhances survival on land- underground germination (growth without photosynthesis)Gymnosperms – naked seed plantsOvules exposed on sporophylls, usually in cones- Ginkgophyta- Medicine, flagellated sperm- Cycadophyta - Central male or female cone, flagellated sperm (ex: sago palm)- Gnetophyta - Non-motile sperm- Coniferophyta- Most diverse- Make pollen cones- Female ovulate cones- Evergreen with needle leaves- Know the pine life cycleLecture 24 (October 27)AngiospermsDerived Characteristics:- Flower – protects ovules with in the ovary- Promotes efficient pollen transfer by pollinators- 4 whorls of modifies leaves- Know the parts and their functions- Flowers can be missing parts (incomplete) Unisex flowers – only male or female (carpels or stamens) No petals – wind pollinated Inflorescence – groups of flowers more attractive to pollinators (ex: bluebonnet, sunflower)- Floral scent and color attracts pollinators- Nectar and pollen keeps pollinators coming- Coevolution of plants and pollinators - same species of pollinators go to the same species of flower- Some flowers do not reward pollinators (ex: orchid with wasp pheromones)- Fruit – enhances seed dispersal- Protects dormant seed- Derived from ovary tissue after fertilization- Fleshy fruit from ovary wall contains seeds (eaten by animals)- Dry fruit dispersed by wind, water, or animals (also protects the dormant seed)Lecture 25 (October 29)Angiosperm life cycle- Pollen grains from anthers- Ovules enclosed within ovary- Pollen lands on stigma- Double fertilization with 2 sperm nuclei- One fertilizes the egg  zygote- Other fuses with 2 central nuclei forming a 3n food supply/endosperm)Anthophyta – includes extant angiosperms3 basal clades: amborella, water lilies, star aniseMagnoliids are separateMonocots - Large endosperm and 1 cotyledon (ex: grasses, grains, palm trees, some garden plants)Eudicots- Endosperm absorbed into 2 cotyledons (ex: most fruits, veggies, trees and shrubs)Fungi - Multicellular and terrestrial- Except for aquatic chytrids and unicellular yeasts- Mycelium – main fungus body for feeding and growing- Usually underground or within a host- Network of filamentous hyphae- Hyphae- Secretes hydrolytic enzymes and acids to digest simple organic materials- Simple organic molecules absorbed (absorptive heterotrophs)- Made of tubular cells with rigid cell walls of chitin- Multicellular hyphae allows cytoplasmic streaming Septae – septum with pores Coenocytic – multi nuclei, no cross walls- Rapid growth toward new food with huge surface area for absorption- Some specialized hyphae Haustoria – penetrate cell walls of plants, but not the plasma membrane Some hyphae catch nematodesLecture 26 (October 31)Fungus reproduction (not chytrids)- Haploid spores made in sexual and a sexual cycles- Germinate on food source- Each spore grows into a haploid mycelium- Sexual cycles do not make male and female gametes- Only +/- mating types3 steps to form a zygote:1. Plasmogamy – fusion of haploid +/- hyphae2. Heterokaryotic stage – hyphae with unfused haploid nuclei of both types3. Karyogamy – fusion of +/- haploid nuclei to form a zygoteThe zygote undergoes meiosis making genetically diverse spores. There is never a multicellular diploid stage.- Asexual reproduction is common- Genetically identical spores made by mitosis that grow into mycelium (mold)- Fragmentation of mycelium can grow into new individuals- Yeasts can bud off into daughter cells by mitosisPhylogeny - Opisthokonts- Unicellular flagellated ancestor- Some lichen fossils are very old- Early plant roots had mycorrhizae- Phylogeny- Only chytrids have flagellum and are aquaticImportance of fungi- Decomposers- Fungus can break down wood lignin- Dry rot, wet rot, mold, mildew- Mutualists- Mycorrhizae – close association with most plant roots Helps plant absorb water and minerals Increases surface area Fungus gets sugars from plant- Lichens – close association with photosynthetic unicellular chlorophyte or cyanobacteria- Fungus gives framework, water and minerals- Algae/cyanobacteria gives sugar from photosynthesis- Soredia – reproduce as dual organism- Pioneers on bare rocks and soils for plants- Pathogens- Infect plants (ex: rust, smut, ergot, molds)- Infect animals (ex: chytrid)- Infect humans (mycosis- infection due to fungus)- Medicine and research- Antibiotics and other meds- Genetic research- Food- Fermentation (beer & bread)- Food processing (bleu cheese, soy sauce)- Poisonous fungiLecture 27(November 3)Animal diversityStructure- Multicellular ingestive heterotrophs- No cell walls- Cells joined by extracellular proteins (esp. collagen)- Specialized nerve and muscle cells- Unique to animals- Organized into tissuesLife cycle- Mostly sexual reproduction- Most have separate sexes- Hermaphrodites have male and female structures in one organism- Asexual in some- Budding, fragmentation, parthenogenesis- Always diploid except eggs and sperm- Embryonic development- Similar genes that control development- Zygote  cleavage  blastula- Gastrulation Forms gastrula with blastopore archenteron Creates germ layers (endoderm and ecdoderm)- Most have a larval stage before adult stage- Differs in form, function, and habitat from adult- Undergoes metamorphosis to adult formAnimal history- Unikonts and opisthokonts- Choanoflagellates are the closest protest group to animals- Collar cells found in some animals-