all living organisms that lack a nuclear membrane

bacteria and archaea differ in DNA sequences

oldest living organisms = bacteria (~3.4 bya)

Most hardy

survive in freezing to boiling

grow in hot acidic environments

living off hydrogen and co2 derived from inside rocks

pioneer species

3.4 bya

anaerobic

didn't produce oxygen

energy from inorganic compounds

carbon from CO2

Chemical transformations are highly diverse

Still discovering metabolic capabilities of bacteria

uses: sewage treatment, digestion of crude oil, pesticides, synthesis of vitamins, antibodies

Incineration releases dioxin

A: Control dilution nutrient salt

B: Bacteria (mixture) and

C. bacteria (mixture) and nutrient

Energy Source: Light

Carbon Source: CO2

Photosynthetic prokaryotes (ex cyanobacteria), plants, certain protists (algae)

Energy Source: Inorganic chemicals

Carbon Source: CO2

certain prokaryotes (ex: Sulfolobus)

Energy Source: Light

Carbon Source: Organic Compounds

Certain prokaryotes: Rhodobacter, Chloroflexus

Energy Source: Organic Compounds

Carbon Source: Organic Compounds

Many prokaryotes, protists, fungi, animals, and some plants

Energy from sunlight

Carbon from CO2

Electrons from inorganic sources

anaerobic bacteria evolved photosynthesis capability ~ 2.7 bya

Photosynthesis:

What mode of nutrition is this?

Cyanobacteria

(photoautotroph)

Photosynthetic Prokaryotes that generage oxygen

Evolved about 2.7 bya

2.7 - 2.2 BYA - Atmospheric Oxygen

oxidation of iron containing rocks

Banded iron formations are evidence of the vintage of oxygenic photosynthesis

Nitrogen fixing bacetira in root nodules of legumes

Nitrogen fixing soil bacteria

Decomposers (aerobic and anaerobic bacteria and fungi)

Nitrifying Bacteria

Denitrifying Bacteria

Occurred After existence of atmospheric O2

1.2 Billion Years Ago

Unicellular bacteria engulf other bacteria

Engulfed bacteria become organelles in host cell

Explains great diversity of Protists

Endosymbiosis evolved many times

Mitochondria (derived from bacteria)

Plastids (derived from another type of bacteria)

Nucleus 

Nuclear genome (derived from host bacteria)

First Evolved Eukaryotic Organisms

Include: Algae, seaweeds, slime molds, protozoa, 30 phyla recognized by taxonomists 

Microscope single celled animals to huge algae, such as kelp

Paraphyletic

Protist carried by tsetse fly that infects mammals by sucking blood

causes extreme lethargy and fatigue

Flagellated Protist

the only drug approved for treating giardiasis in the U.S. is furazolidone (Furoxone) for 7-10 days

feeds mainly on bacteria, rows of cilia along a funnel shaped oral groove; move food into the cell mouth where the food is engulfed by phagocytosis

food vacuoles combine with lysosomes; follow a looping path

undigested contents of food vacuoles are released when the vacuoles fuse with specialized region of the plasma membrane that functions as an anal pore

photosynthetic, unicellular

found in photic zone

concentrate dissolved silica (SiO2)

Base of Marine and Freshwater Food chains

Kelp forest Ecosystem - Algal Protist - Brown Algae

p.580

Multicellularity evolved many times from unicellular protists

Brown kelp more closely related to unicellular protist than any other large algae

paraphyletic

extremely diverse

eukaryotes

evolved from endosymbiosis of two or more types of prokaryotes

reproduce sexually or asexually

Red Algae

K. Protista

Nori Traditional Japanese food

Wrap for Sushi

Diatoms

Brown Algae

Golden Algae

Water Molds

Form Chitonous Spores

Have chitinous cell walls

Absorptive nutritional mode

First evolved 460 million years ago

DNA more similar to K. Animalia than K. Plantae

Polysaccharide containing nitrogen

Plant Cell Walls: Cellulose

Fungus Cell Walls: Chitin

More similar to K. Animalia than K. Plantae

Fungi and Plants probably colonized land together

Earliest terrestrial ecosystems were dependent on fungi as decomposers and symbionts

Some mutualistic: absorb nutrients from hosts but hosts benefit

Some parasitic: absorb nutrients from living hosts

Example: Lichens

symbiosis of photosynthetic microorganism held in fungal hyphae mesh

Photosynthetic Organism and Fungus

Algae or Cyanobacteria

Asexual and sexual reproduction fungus

SOREDIA: fungus and algae fragment

break down rock physically and chemically

Fungal Diseases

Fungal Foods

Fungal Medicine

Athlete's foot, Valley Fever, Powdery Mildew

Food: Mushroom, Tuffles

Medicine: Penicillin

highly variable in coloration

difficult to identify

poisonous effects often delayed making treatment impossible

people have different sensitivities

Phytophthora

Affects lots of trees

Many species killed, but some survive

Mostly CA, now UK, Florida; accidental shipment of contaminated nursery stock

Phytophthora infestans

Fungal pathogen oomycetes

Killed over 1 million Irish

Caused mass immigration of > 1 million

K. Fungi Div. Basidiomycota

Armillaria Ostoyae: "shoestring rot"

root rot for forest tree

cover over 10km2 in oregon

2000-8500 yrs old

605 tons!

Yeast

Flagellated gametangia of chytrids

Form MYCELIUM, a mass of connected hyphae

Two types of hyphae: with and without septa

Reproduction with chitinous spores

(formed sexually or asexually)

Spores 2 - 75 microns in diameter; suspend in air for long time and travel widely

Flagellated 

Unicellular

Closely related to animals: opisthokonts (with posterior flagellum)

Diverged from animals 1.5 billion years ago

Oldest Fossil fungi: 460 mya

Moved ashore with earliest plants as mycorrhizae

Oldest Fungal Group!

Flagellated stage: motile zoospores

Link to Animals

Aquatic

Some parasitic

Some symbiotic relationships with plants

Two mating types, +, and -

Plasmogamy forms zygosporania (resistant to freezing and drying, form during deteriorating conditions)

Non septae mycelium

Formerly classified as zygomycetes

Arbuscular mycorrhizae (endomycorrhizae)

hyphae enter root cells and branch into arbuscules

Cup Fungi, morels, truffles, yeast

half of the species in lichen

dutch elm disease, chestnut blight

asexual reprod produces CONIDIA, naked spores

fruiting bodies: ascocarps that contain asci which contain the sexually formed spores, ascospores

8 ascospores per ascus

chain reaciton in release of spores from asci

Polysaccharides -- Chitin

(plants and many protists contain cellulose)

Cell division

Nucleus is unit of reproduction not cell

centrioles are absent (except in chytrids)

intervening dikaryotic stage (1n+1n) occurs before parental nuclei fuse and form a diploid nucleus

Can be short or last for most of the life of the fungus

Some produce specialized mycelial structures to house production of spores

Spores are most common means of reproduction among fungi and when in a suitable place, germinate, giving rise to new fungal mycelium

lack mitochondria

fungus

presence of mitochondrial genes

obligate parasites that cause death

aquatic, flagellated fungi

motile zoospores

single flagellated zoospore

Chytridiomycota

digest cellulose in herbivores

cows depend on them

fungus

zoospores have multiple flagella

Fungi that produce zygotes

not monophyletic

common bread molds

sexual reproduction: zygotes form inside a zygosporangium

all are haploid except for the zygote nuclei

asexual reproduction more common: hyphae produce clumps of erect stalks, called sporangiophores which form sporangia, which are separated from septa. Spores are shed. 

likely made the evolution of plants possible

arbuscular mycorrhizae

need a host plant (mutualistic)

lineage based on analysis of rRNA

Glomeromycota

intracellular associations with plant roots

The Sac Fungi

75% of known fungi

Sexual production occurs in ascus (karyogamy happens here) followed by meiosis

Asexual reproduction happens in conidiophores 

obligate symbiosis: essential for survival

facultative symbiosis: fungus can survive without host

endophytic fungi live iside intercellular spaces in plants

produce alkaloids that may protect plants from parasites

smybiotic assocations between a fungus and a photosynthetic partner

fungi in lichens unable to grow normally without their photosynthetic partners, and the fungi protect their partners from strong light and desiccation

strongly colored bc of pigments that protect photosynthetic partner from light

vary in sensitivity to pollutants in atmosphere

bioindicators of air quality

fungus and root

fungi are extensions of the root system - increase the amount of soil contact and toatl surface area for absorption and aid in nutrient absorption

plant supplies organic carbon to fungus

am: fungal hyphae penetrate the outer cells of the plant root, forming coils and extending into the surrounding soil

ecto: hyphae surround but do not penetrate cell walls of roots