Biology of Fungi and Lichens 2023 with verified questions and answers

Endophyte a fungus living with a plant as a parasite Saprotroph feeds on dead decaying organic matter Woronin Body septal pore block in fungal hyphae Anastomosis connection between parts of any branching system Conidium an asexual spore formed by abstriction at the top of a hyphal branch Ascogonium female sexual organ in ascomycetes Antheridium male reproductive structure producing gametes Trichogyne prolongation of ascogonium that serves as a receptive structure for spermatium Ascus (pl. Asci) sac in ascomycetes in which the sexual spores are formed Conidiogenesis the production of conidia by fungal cells Anamorphic conidiogenesis stage Teleomorphic ascus development stage Blastic tip of the hypha balloons outward to form a conidium Thallic tip of a hypha becomes cut off by the formation of a septum Schizolytic the septum disintegrates to release the conidium Rhexolytic the cell beneath the conidium disintegrates to release the conidium Conidioma (pl. Conidiomata) an aggregation of conidiophores producing conidia Coleomycete conidiophores within a compartment Hyphomycete exposed conidiophores Ostiole a small opening or pore in the fruiting body of a fungus Bacon the back and sides of the hog, salted and dried or smoked, usually sliced thin and fried for food Synnemata conidiophores arranged in parallel bundles Sporodochia layer of short conidiophores in a cushion shape Unitunicate layers of the ascus wall do not separate during spore release Prototunicate spherical in shape and has a thin wall that either ruptures or disintegrates to release spores Bitunicate an ascus in which the outer and inner layers of the ascus wall separate during ascospore release Fissitunicate a bitunicate ascus has a distinctly bilayered wall, with the outer layer being rigid and the inner layer being expandable. As it matures, the thin outer layer splits and the thick inner layer absorbs water and expands upward. The ascus stretches up into the narrow neck of the ascoma, and the ascospores are expelled. Operculate (unitunicate asci) - ascus discharges through an opening when the lid (operculum) opens eg. pezizales Inoperculate (unitunicate asci) - ascus does not have a lid, but has a diversity of other specialized openings such as jack-in-the-box, annulus or apical ring, or apical pores or splits Evanescent ascus has no opening, but the wall disintegrates to release spores Jack-in-the-box - fissitunicate or bitunicate asci - two ascus walls - two stage process - eg. loculoascomycetes Apical ring or Annulus - thickened extension of apical wall - elastic annulus is everted - pressure causes spores to pass through individually and become expelled Apical pores or splits - spore squeezed through pore and expelled - passive release through split - single ascus wall Hymenium fertile layer in a fungus with asci and paraphyses Apothecium the fruit of certain lichens and fungi: usually an open, saucer-shaped or cup-shaped body, the inner surface of which is covered with a layer that bears asci Perithecia the fruiting body of ascomycetous fungi, typically a minute, more or less completely closed, globose or flask-shaped body enclosing the asci Pseudothecia - develops inside a stroma with digested locules - similar shape as perithecia Cleistothecia - enclosed case with asci but no opening - wall must disintegrate or be eaten by animals Gymnothecium - a type of cleistothecium with loosely woven walls - a case (ascocarp) made of loosely woven hyphae containing asci and spores Homothallic having all mycelia alike Ascoma a fruiting body that bears asci Fermentation anaerobic metabolism of glucose and other sugars by pyruvic acid into CO2 and ethanol Phialide the flask-shaped projection from the top of a conidiophore of certain fungi Conidiophore a conidium-bearing hypha or filament Mycotoxins - secondary metabolites capable of causing disease and death in animals - resistant to degradation so they remain in the food chain Lichen a self-supporting association of a fungus and a green alga or cyanobacterium resulting in a stable thallus of specific structure Pycnidium a flask-shaped fungal compartment where conidia are produced in lichens Soredia - small clumps of hyphae enclosing a few algal cells - hydrophobic and are dispersed by wind after the initial detachment from a rain drop - small clusters of fungal hyphae and algal cells; produced over entire surface or in limited areas of the thallus; hydrophobic and dispersed by wind Isidia - are large, upright cylindrical structures which contain both symbionts - increase the surface area of the lichen thallus but can also become detached and then function as vegetative propagules - cylindrical or bulbous structures on thallus surface with both symbionts; covered in cortex; shapes vary; may be produced in different locations on thallus; increase thallus suface area for photosynthesis and can break off for dispersal Squamules a small, scalelike thallus lobe of certain lichens Lichenicolous Lichen mycobionts that have taken the ultimate step of poaching their photobiont from an existing lichen thallus in order to establish their own independent thallus Lichenicolous Fungi fungi that feed on the photosynthetic products of a lichenized photobiont without ever establishing an independent thallus, while yet others destructively parasitize the host lichen Lichen Acids many secondary metabolites of lichens have acidic properties and lichen grazing animals even tend to avoid their consumption Rostrum a beak-like process or extension of some part Podetium an apothecium-bearing vertical thallus arising from a horizontal primary thallus eg. typical of Cladonia Hypogeous underground Epigeous growing on or close to the ground Pre-thallus hyphae that develop into mycelium that envelopes clusters of algal cells Crustose Growth Form entire lower surface of thallus is directly attached to substrate Foliose Growth Form leafy thallus attached to substrate by special attachment organs Fruticose Growth Form - pendant thallus attached to substrate by a single attachment organ - upright or pedant in nature eg. Cladonia or Usnea Usnic Acid - acid produced by certain fungi that screens out UV light to protect the algae and produces a yellow colour eg. Cladonia - kills insects, anti-bacterial; absorbs light Substrate - the surface on which a lichen is attached - will also influence the lichen colonization - based on 3 properties: texture, water relations, chemistry (pH) Bark/Wood Substrates - rough bark can trap lichen propagules - water is retained in crevices of bark - bark pH depends on tree species, pollution, moisture Rock Substrates - limestone is more porous than granite - water is easily absorbed by limestone - ph depends on pollution, moisture and affects availability of nutrients Mineral Weathering - provides nutrients for lichens where that may not be possible for other types of organisms - Release of CO2 in respiration + water = H2CO3 which lowers pH and solubilizes minerals (Al and Fe) Hyphal Rock Penetration - as humidity changes within an environment, the repeated expansion and contraction of the hyphae causes the rock crevices to open and release nutrients - combination of physical and chemical methods Atranorin - increases with high light levels and is used to reflect light and protect algae from UV rays - inhibits growth of plants and insects, reflects light Fumarprotocetraric Acid inhibits growth of plants; hydrophobic properties Salazinic Acid red-brown dyes; binds to minerals Glucane inhibits HIV integrase Gyrophobic Acid purple dyes Vulpinic Acid inhibits insect growth, toxic to meat eaters; used to kill wolves around sheep farms; source of bright yellow dyes Polyketides - are a class of secondary metabolites produced by certain living organisms in order to impart to them some survival advantage - many mycotoxins produced by fungi are polyketides - deposited on the outside of fungal hyphae as crystals - amount of polyketides in each thallus are regulated by light levels Norstictic Acid - decreases with high levels of light by decreasing the humidity in the medulla - needed to maintain low moisture levels for optimal photosynthesis Poikilohydry thallus can tolerate dehydration and recover without damage to cells and tissues Coprophilous fungi that grow on animal dung Phototropic - method of maximizing a plants exposure to sunlight to produce food - disperse spores away from dung in P. ascobolus Mycorrhiza is a symbiotic association composed of a fungus and roots of a vascular plant