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What is a Protist? Classified in Kingdom Protista
“Protista” means “very first”Loosely related group of micro orgs.Believed to evolved 1.5 billion years ago
Why is this name fitting?Protists are the simplest Eukaryotes
• Nucleus and Membrane Bound Organelles
Evolutionarily – could have been “ancestor” eukaryote organism
Classification Kingdom Protista – All Protists Problem to classify because of diversity Classified further by mode of nutrition
1. Animal Like Protists - Heterotrophic• Must EAT their food• Move around like animals• Unicellular UNLIKE Kingdom Animalia
2. Plant Like Protists - Autotrophic• MAKE their own food• Lack organs/parts UNLIKE Kingdom Plantae
3. Fungal Like Protists – Decomposers/Parasites• ABSORB their food externally.• Lack chitin and have centrioles UNLIKE Kingdom Fungi
Animal-Like Protists Once called Protozoans –“First Animals” Make up 70 Percent of all Human Parasites Why not animals? Unicellular! 4 Phlya of Animal-Like Protists Based on how they move
1. Zooflagellates use flagella to move
2. Sarcodines move by extension in cytoplasm
3. Ciliates use cilia to move
4. Sporozoans do not move at all
1. Zooflagellates(Phylum Zoomastigina)
Swim using flagellaWhiplike tails
“Eat” food through cell membranesEx: Trypanosoma – African
Sleeping SicknessEx: Dileptus
Parasitic or free living Can use asexual and sexual
life cycles
2. Sarcodines(Phylum Sarcodina AKA Phylum Rhizopus)
Obtain food and moves by projections of cytoplasm called pseudopods• Ameoboid movement –
streaming movement of cytoplasmic projections
• Contractile Vacuole – controls water in cell
• Food vacuole – holds food• Ex: AmeobasEx: Entameoba causes
amebic dysentery
3. Ciliate (Phylum Ciliophora) Use cilia to move Very organized anatomy
2 nuclei: macronuclei and micronucleiOral Groove – mouth-like structureGullet – stomach like structureAnal pore – waste releaseContractile vacuole – store, pump water Pellicle – rigid protein cover, anchors
flagella, ciliaTrichocysts – projections that protect
the cell Ex: Paramecium
Conjugation in Ciliates Typically use Asexual
Binary Fission If stressed can use
ConjugationSexual
recombination of genes – swap micronuclei
NOT Reproduction (No NEW individuals)
4. Sporozoans(Phylum Sporozoa AKA Apicomplexa)
Cannot move on their own
Obligate parasites Complex life cycles that
involve many hosts Reproduce using
sporozitesEx: Plasmodium,
Causes Malaria
Sporozoans Other infectious parasites
• Giardia lambalis- diarrheal illness caused by a microscopic parasite usually found in water associated with animal feces
• Cryptosporidium – diarrheal illness associated with animal feces; mass outbreaks occur after floods (over 400,000 after the Milwaukee floods of 1993)
• Toxoplasma gondii - parasite that reproduces in cats and is released in their feces; can infect humans. Effects include miscarriages, psychology, and higher ratio of male births!
Ecology of Animal Like Protists Not so Good: Can be parasitic/cause
diseaseMalaria, African Sleeping Sickness,
Cryptosporidium Good: Symbiosis
Termites have beneficial animal like protist called Trichonympha in their stomachs
• Break down cellulose in wood so termites can use it as food
Fungus-Like Protists
Fungus-like protists are heterotrophs that absorb nutrients from dead or decaying organic matter.Unlike true fungi, however, fungus-like
protists have centrioles and lack chitin in their cell wall.
The fungus-like protists include:1. Cellular slime molds2. Acellular slime molds3. Water molds
1. Cellular Slime Molds
Cellular slime molds belong to the phylum Acrasiomycota.Spend their life as an
independent individual that feeds, grows, and divides by cell division
During harsh times, individuals can form large slug-like MULTICELLULAR colony with a distinct cell membrane to reproduce.
Cellular Slime Molds in Action
http://www.princeton.edu/main/news/archive/S26/40/20I71/index.xml?section=mm-featured
2. Acellular (Plasmodial) Slime Molds
Acellular slime molds belong to the phylum Myxomycota. During the course of
their life cycle, their cells fuse to produce structures with many nuclei known as plasmodia (a mass of cytoplasm that contains many diploid nuclei but no cell walls or membranes).
THE MOVING, FEEDING FORM OF A PLASMODIAL SLIME MOLD IS A MULTINUCLEATE BLOB OF CYTOPLASM – THIS IS THE FEEDING STAGE OF THE LIFE CYCLE
3. Water Molds
Water molds are members of the phylum Oomycota.
They thrive on dead or decaying organic matter in water and are plant parasites on land.
Ecology of Fungi Like Protists Slime molds and water molds are MOST important
recyclers of organic material
Some can be harmful Plant diseases ex. Irish Potato Famine – water mold
Phytophtora infestans*overgrowth of water mold caused by wet and
cool conditions
Why is the earth not littered with dead orgs? Tissues broken down by Fungi Like Protists and other
decomposers
Plant Like Protists Main Characteristic: Chlorophyll
Green Pigment- traps light, carries out photosynthesis
Evolved from symbiosis of photosynthetic bacteria and larger, heterotrophic bacteria
Commonly called “Algae” Many contain cell wall like plants Lack plant organs/parts Classification
Unicellular – unique characteristics – 4 phylaMulticellular – type of pigments (color) – 3 phyla
Plant-Like Protists: Unicellular Algae
The 4 phyla of unicellular plant-like protists (AKA algae) are:
1. Euglenophyta
2. Pyrrophyta
3. Chrysophyta
4. Bacillioriophyta
1. Phylum Euglenophyta
Euglena- plantlike unicellular algae w/ animal like characteristics Animal – like – can be heterotrophic,
gullet, flagella Plant – like – chloroplasts, starch storage,
eye spot Cluster of reddish pigments known as an
eyespot which function to help find sunlight for photosynthesis
Euglenas do not have a cell wall, but they do have a pellicle.
Euglenas reproduce asexually-binary fission
Why plant-like? Chloroplasts!
2. Phylum Pyrrophyta - Dinoflagellates
Dinoflagellates are unicellular plant-like that can be photosynthetic or heterotrophic 2 flagella wrapped around in grooves between 2 thick plates
of cellulose that protect the cell Most reproduce asexually by binary fission Many species are bioluminescent – fire algae Can have red, green or yellow pigments Can produce neurotoxins - Red Tide
Algal Blooms-Unicellular plant like protists can grow rapidly in areas where sewage is discharged.
-These rapid growths are known as algal blooms.-Algal blooms quickly deplete the water of nutrients, and the cells of the bloom begin to die in great numbers.-Decomposition of these dead algae can rob water of its oxygen, choking its resident fish and invertebrate life--Ex: Red Tide
3. Phylum Chrysophyta – Golden Algae
Members of the phylum Chrysophyta are a diverse group of plantlike protists that have gold-colored chloroplasts/pigments.
• includes yellow-green algae and golden-brown algae
• reproduction can be sexual or asexual• colonial• Store food as oil not starch
4. Phylum Bacillariophyta - Diatoms
Unicellular plant-like protists that produce thin, delicate cell walls rich in silicon – glass likeVariety of photosynthetic pigmentsAmong the most abundant organisms on Earth!
• Make LOTS of Oxygen!Found in toothpaste, filtersBioluminescent
Multicelled Algae Chlorophyll & Acessory Pigments
Multicellular Plant Like Protists are classifed by type of photosynthetic pigments they contain.
• In adapting to conditions of limited light, various groups of algae have evolved different forms of chlorophyll:
• Chlorophyll a• Chlorophyll b• Chlorophyll c
• Each form of chlorophyll absorbs different wavelengths of light:
• Accessory pigments that absorb light at different wavelengths than chlorophyll.
Multicellular Plant-Like Protists: Red, Brown, and Green Algae
The 3 phyla of algae that are largely multicellular are commonly known as:5. red algae6. brown algae7. green algae
• A major difference among these phyla are their photosynthetic pigments.
5. Phylum Rhodophyta – Red algae
Live at great depths due to their efficiency in harvesting reddish accessory pigments called phycobilinsphycobilins absorb blue light (reflect red)Most red algae are multicellular and can live
in waters from the polar regions to the tropicsCarageenan – red algae compound in foods –
“gel”Example: Chondrus crispus (irish moss)
6. Phylum Phaeophyta – Brown Algae
Brown algae contain chlorophyll a and c, as well as a brown accessory pigment, fucoxanthin (foo-co-zan-thin)
All brown algae are multicellular and most live in cool, shallow, coastal marine waters.Examples: giant kelp, Sargassum, and
Fucus
7. Phylum Chlorophyta – Green Algae
Green algae share many characteristics with plants, including their photosynthetic pigments and cell wall composition:have cellulose in cell wallcontain chlorophyll a and bstore food in the form of starch
Green algae can be found in fresh or salt water:Some are single cells (ex: Chlamydomonas)Some form colonies (ex: Volvox)Some are multi-cellular (ex: Ulva)
Green Algae
Chlamhydomonas
unicellular
green algae
Volvox
colonial
green algaeUlva
multicellular
green algae
Spirogyra
Multicellular green algae
Ecology of Plant-Like Protists
Produce 90% of all oxygen on earth!
Phytoplankton = bottom of food chain
Human foods Ice creams Chocolate Sushi
Plastics Waxes Paints Agar Can release toxin & choke
environment – algae bloom
Protist Graphic Organizer Kingdom Protista Fungi-like
Absorb food
Animal-likeEat food
Plant –likePhotosynthetic
unicell multicell
Create a graphic organizer on your sheetFill in the phylum names under plant, animal and fungi-like…under each phylum, give an example
General Characteristics of Fungi
Ubiquitous Decompose HETEROTROPHIC Some are parasitic, some
are mutualistic Have plant & animal
characteristics
PLANT-Like = many are anchored in the ground; cell walls (but NOT of cellulose)
ANIMAL-Like = Heterotrophic On the living and on
dead• Parasites • Saprobes
Fungi General Characteristics Mostly multicellular
Yeast unicellular They have a nucleus
Many have multiple nuclei Much of their lifecycle is haploid! They have a cell wall
Made of chitin – a protein/carb complex Digestion is EXTRACELLULAR!
They secrete an enzyme that breaks down nutrients THEN they take them in
NO PHOTOSYNTHESIS!
FUNGI STRUCTURE Made of thin filaments
= hyphae (fuzzy) Hyphae can grow as
individual cells or may fuse together to form coenocytic threads
there are different types of hyphae
• some for reproduction, some for growth, some for stability (sturdy)
Hyphae that form a web and work together = Mycelium
More about their structure….
The visible part of a fungus is only a very small part of the mycelium….
….most is underground
FUNGI REPRODUCTIONSome reproduce
asexually, some sexually – most both Asexual reproduction
• Fragmentation/budding,• Spores (clones)
• Spores can be thick walled & resist water loss
(ie, the fungus won't dry out)
Sexual reproduction• haploid +/- hyphae fusion
diploid gametangium• meiosis haploid spores
haploid organism
Classification
4 Phyla 1. Zygomycota 2. Ascomycota 3. Basidiomycota 4. Deuteromycota*
--All have different hyphae types & reproductive structures
-- Classified based on how they reproduce!
1. Phylum Zygomycota “Zygote fungi” Reproduce sexually &
asexually Formed from 2
different gametangium that fuse Gametangium zygospore
Ex. Bread Mold, Athlete’s foot (Tinea pedis)
Zygomycota Hyphae
a) Rhizoid Anchor the fungus in its food
sourceb) Stolon
Run along the surface of the food source
• Give rise to 2 mating forms (“+” and “-”)
• Sexual reproduction & growth
c) Sporangia Also called “fruiting bodies” Swell at the tips of
sporangiophores• Contain the spores used for asexual reproduction
Phylum Ascomycota Sac fungi Reproduce sexually & asexually Spores (called ascospores) are
made in a sac is called an ascus
Conidiophores form and help disperse haploid spores
Important fermenters Convert sugar to CO2 & alcohol
Ex. Yeasts (with no hyphae), powdery mildews, food molds
Yeast = only unicellular fungus! Infectious: candidiasis, ringworm
Phylum Basidiomycota
Club fungi Reproduce sexually &
asexually Forms a club shaped
structure = Basidia; this is where spores are made = Basidiospore
Cap = where reproduction takes place
Ex. Mushrooms, puffballs, smuts
What is this mushroom cloud?
Spores! Releasing millions! Only 1-2/million
spores may develop into mature fungus
World’s Largest Organism Honey Mushroom (Armillaria ostoyae) Blue Mountains of Oregon Mycelium = 1,665 football field area Mass is over 2,000 tons Why can we only see so
little?!?!
Phylum Deuteromycota
“Imperfect Fungi” Reproduce
asexually only Typical Molds Uses:
Cheeses Candy Antibiotics (penicillin) Illnesses
Penicillin
1928, Sir Alexander Fleming observed that colonies of the bacterium Staphylococcus aureus could be destroyed by the mold Penicillium notatum
Aspergillus
Can cause severe lung infection
Can form endospores 2-4,000 year old
endospore of Aspergillus niger may have caused the death of initial archeology team members excavating tombs
a) Lichens SYMBIOSIS of a fungus (usually an ascomycetes)
with an algae OR a cyanobacteria
The fungal partner benefits by getting sugars, its only nutrients, from the algae which photosynthesize.
The algal partner gets protection and nutrients broken down by the fungal partner.
QUIZ TIMEAnswer Questions - True or False…if false CORRECT it!
1. Fungi are autotrophs (use photosynthesis).
2. Fungi spend much of their lives in a haploid state.
3. There are 3 Phyla of Fungi. 4. Fungi have cell walls made of
cellulose. 5. Fungi are made up of special cells
called hyphae.