Chapter 12 Eukarya

Crustose

(of lichens) having a thin crusty thallus that adheres closely to the surface on which it is growing. Encrusted in substratum.

characteristics of algae (1 of 2)

- Locations depend on nutrient availability, wavelengths of light, and surfaces to attach - Thallus: body of multicellular algae --Consists of holdfasts, stipes, and blades - All reproduce asexually - Multicellular algae can fragment or reproduce sexually via alternation of generations

Apicomplexa (plasmodium)

- causes malaria - sexually reproduces in the anopheles of mosquito - a mosquito injects a sporozoite into its bite and the sporozoite undergoes schizogony in the liver; merozites are produced - merozites infect red blood cells forming ring stage inside the cell - red blood cells rupture and merozites infect new red blood cells

selected phyla of algae (dinoflagellates)

- cellulose in plasma membrane - unicellular - neurotoxins (saxitoxins) cause a paralytic shellfish poisoning.

Cestodes (2 of 2)

- humans as intermediate hosts eggs are ingested and hatch in the intestine - larvae migrate to the liver or lungs and develop a hydatid cyst - echinococcus granulosus

Medically important protozoa

-Feeding grooves (Excavata) -Diplomonads -Parabasalids -Euglenozoa -Amebae -Apicomplexa -Ciliates

Algae

-Not a taxanomic group -unicellular or filamentous photoautotrophs - lack roots stems and leaves - mostly aquatic - water is necessary for growth and reproduction

coenocytic hyphae

A fungal filament that is not divided into uninucleate cell like units because it lacks septa.

Mycelium (mycelia)

A mass of long filaments of cells that branch and intertwine typically found in molds.

Selected Phyla of Algae

Brown Algae (kelp) cellulose and alginic acid cell walls - multicellular and macroscopic - produce align - thickener used in foods

Vegetative (fungal colonies)

Cells involved in catabolism for growth

Zygomycota

Conjugation fungi Coenocytic hyphae Produced asexually: sporangiospore Produced sexually: zygospore Forms when nuclei of two similar cells fuse

Roles of algae in nature

Fix CO2 into organic molecules Produce 80% of Earth's O2 Algal blooms Oil production Symbionts of animals

Assume you isolated a single celled organism that has a cell wall . How would you determine that it is a fungus and not a bacterium?

Fungi are eukaryotic not prokaryotic. Fungi's cell membrane has sterols present bacteria don't. Fungi have sexual and asexual reproductive spores. Bacteria have endospores. Fungi's metabolism are limited to heterotrophic; aerobic; facultatively anaerobic.

Life Cycle of Fungi

Fungi reproduce sexually and asexually via the formation of spores that detach from the parent and germinate into a new mold

Selected Phyla of Algae (green algae)

Green Algae - cellulose cell walls - unicellular or multicellular -chlorophyll a and b -store starch - gave rise to terrestrial plants

nutritional adaptations of fungi

Grow better at pH of 5 Grow in high sugar and salt concentration; resistant to osmotic pressure Can grow in low moisture content Can metabolize complex carbohydrates

what are fungi?

Include mold, fleshy fungi (mushrooms puff balls) and yeasts

Nematodes (3 of 3)

Larvae infective for humans strongyloides - reemerging infection nector americanus and ancyllostoma duodenale hookworm enter the skin and are carried to the intestines . Dirofilaria immitis - spread by mosquitoes; causes heartworm

plasmodial slime molds

Mass of protoplasm with multiple nuclei; moves as a giant ameba

Thallus (body) of lichens are made of:

Medulla—hyphae grown around algal cells Rhizines (holdfasts)—hyphae projections below the body Cortex—protective coating over the algal layer

Vegetative Structures of Fungi

Molds and fleshy fungi The Fungal Thallus (body) consists of hyphae filaments; a mass of hyphae is a mycelium. Septate Hyphae- contain cross walls - coenocytic hyphae: do not contain septa - vegetative hyphae obtain nutrients while arial hyphae are involved with reproduction

characteristics of helminths

Multicellular eukaryotic animals Specialized to live in hosts May lack digestive system Reduced nervous system Reduced or lacking locomotion Complex reproductive system

Lichens

Mutualistic combination of a green alga (or cyanobacterium) and fungus

Fungal Diseases

Mycosis: fungal infection Systemic mycoses: deep within the body Subcutaneous mycoses: beneath the skin Cutaneous mycoses: affect hair, skin, and nails Superficial mycoses: localized (e.g., hair shafts) Opportunistic mycoses: fungi harmless in normal habitat but pathogenic in a compromised host

Microsporidia

No sexual reproduction is observed, but probably occurs in a host No mitochondria Obligate intracellular parasites

vegetative structures of yeasts

Nonfilamentous and unicellular Budding yeasts divide unevenly Fission yeasts divide evenly

Selected Phyla of Algae (Red Algae)

Red Algae - have branched thalli - most are multicellular - harvested for agar and carrageenan - some produce a lethal toxin

characteristics of protozoa

Require a large supply of water Many have an outer protective pellicle, requiring specialized structures to take in food Ciliates wave cilia toward mouthlike cytosome Amebae phagocytize food Food is digested in vacuoles and wastes eliminated through an anal pore

Acosomycota

Sac; Fungi Septate hyphae - Telemorphic Fungi - Produce sexually and asexually - some are anamorphic - lost ability to sexually reproduce produced asexually : conidiospore - produced sexually: ascospore - nuclei morphologically similar or dissimilar fuse in saclike ascus

Economic effects of fungi

Saccharomyces cerevisiae: bread, wine, hepatitis B vaccine Trichoderma: cellulase Taxomyces: taxol Entomophaga: biocontrol Coniothyrium minitans: kills fungi on crops Paecilomyces: kills termites

Sporangiospores

Spores formed in a sac (sporangium)

Dimorphism

The property of having two forms of growth.

Platyhelminthes

Trematodes (flukes) - flat leaf shaped - ventral and oral sucker - fabsorb food throu cuticle covering paragonismus spp- long fluke -schistosoma - blood fluke

Protozoa

Unicellular eukaryotes inhabit water and soil animal- like nutrition complex life cycles

Dimorphic fungi

Yeastlike at 37 C and moldlike at 25 C

Medically Important Fungi

Zygomycota Microsporidia Ascomycota Basidiomycota

protozoa trophozoite

active, motile, feeding stage of protozoa/ feeding and growing form

Lichens (alga)

alga produces and secretes carbohydrates fungus provides holdfast Economic Importance: - dyes - antimicrobial (usnea) - litmus - food for herbivores

Arthropods as Vectors

arthropods are animals with segmented bodies, hard external skeletons, and jointed legs vectors are arthropods that carry pathogenic microorganisms representative classes: arachnida - eight legs crustacea - four antennae insecta - six legs ex: mosquito or tick - mechanical transmission biological transmission - pathogen multiples in the vector - definitive host - microbes sexual reproduction takes place in the vector

Protozoa reproduction

asexual reproduction is by fission budding or schizogony (multiple fission) sexual reproduction is by conjugation some produce a cyst to survive in adverse conditions.

Blastoconidia

buds of the parent cell

Slime Molds

cellular slime mold resemble ameba ingest fungi and bacteria by phagocytosis cells aggregate to form stalks and spore caps that differentiate into spores

Fungi

chemoheterotrophs - decompose organic matter (main decomposers on earth) -aerobic and faculitive anaerobic - responsible for food spoilage and diseases in plants and humans

Basidomycota (club fungi)

club fungi: seperate hyphae produced asexually: conidiospores produced sexually; basidiospores - formed externally on a base pedestal called basidium

contrast mechanisms of conidiospore and ascospore formation.

conidiospore - free spores not enclosed by a spore-bearing sac ascospore- spores formed in ascus

Nematodes (round worms)

cylindrical; complete digestive system - diocecious; males contain spicules - free living and parasitic - eggs infective for humans - ascaris lumbricoides- infect human intestines baylisascaris porcyonis - racoon roundworm trichuris trichura - whipworm enterobius vermicularis- pinworm

Selected phyla of algae (diatoms)

diatoms - pectin and silica cell walls - unicellular and filamentous - store oil produce domoic acid - cause neurological diseases

helminths life cycle

dioecious- separate male and female monoescious- (hermaphroditic) male and female reproductive systems. Egg, Larvae, Adult

fruticose lichen

finger like projections

Arthroconidia

fragmentation of septate hyphae

Condiospores

free spores not enclosed by a spore-bearing sac

Life Cycle of Sexual Spores

fusion of nuclei from two opposite mating strains. Three phases of sexual reproduction: Plasmogamy- haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (-) Karygomy + and - nuclei fuse and form diploid zygote Meiosis - diploid nucleus produces haploid nuclei (sexual spores)

foliose lichen

leaf-like

which fungi are macroscopic and microscopic?

molds and yeasts are microscopic fungi and fleshy fungi (mushrooms and puff balls are macroscopic)

Amebae

move by extending pseudopods - entamoeba histolytica - causes amebic dysentery Acanthamoeba- infects corneas and causes blindness balamuthia - granulomatous amebic ecephalitis

Medically important protozoa (diplomonads)

no mitochondria; multiple flagella

Apicomplexa

nonmotile, obligate intracellular parasites, complex life cycles Toxoplasma gondii - transmitted by cats; causes fetal infection crysporidium; transmitted via feces causes waterborne illness

Selected Phyla algae ( oomycota Water molds)

oomycota (water molds) - cellulose cell walls - chemoheterotrophic -produce zoospores - decomposers and plant parasites phytophthora infestans was responsible for the Irish potato blight P. cinnamoni infect eucalyptus P. ramorum causes sudden oak death

Heleminths

parasitic worms two phyla: platyhelminthes (flatworms) nematoda (round worms)

Euglenozoa

photoautotrophs or faculative chotrophs hemoflagellates - transmittted by bites of blood feeding insects

Life Cycle of Fungi asexaul spores

produced via mitosis and cell division; formed by the hyphae of one organism.

cytoplasmic streaming

protoplasm moves and changes speed and direction to distribute oxygen and nutrients

Cilliates

protozoans that move with cillia arranged in precise rows and have two nuclei- the micro nucleus and the macro nucleus Balantidium Coli is the only human parasite caused by dysentery

Platehelminths Cestodes (tapeworms)

scolex - head that has suckers attatchment absorb food through cuticle porglottids- body segments; contain male and female reproductive organs - humans as definitive hosts - eggs from proglottids are ingested hatch into larvae and bore into the intestinal wall - produce cysticerci - Taenia solium - pork tapeworm

Yeast

simplest fungi (unicellular)

mychorrhizae

specialized mutualistic associations between roots and fungi a root growing in symbiosis with plant roots.

Chlamydoconidium

spore within a hyphal segment

Mycology

study of fungi

Hypahe

the body of mold or fleshy fungus consists of long filaments of cells joined together called hyphae Mass of hyphae is mycellium

Aerial hypha

the portion of the hypha that is concerned with reproduction

vegitative hyphae

the portion of the hyphae that digest and absorb nutrients

How do yeast reproduce?

the simplest fungi reproduce asexually by budding or fission.

Medically important protozoa (parabasalids)

undulating membrane no cyst stage

yeast fermentation

yeast can ferment carbohydrates an ability that is exploited by the brewing winemaking and baking industries.