Tuesday March 8, 2005 BIOL L100 Indiana University Southeast David Partin, Instructor.

TuesdayTuesdayMarch 8, 2005March 8, 2005

BIOL L100 BIOL L100 Indiana University SoutheastIndiana University Southeast

David Partin, InstructorDavid Partin, Instructor

Today’s Plan:Today’s Plan: Quiz #7Quiz #7 Announcements: Announcements:

Exam #2 will be one week from todayExam #2 will be one week from today Study session on ThursdayStudy session on Thursday Grade book is completely up-to-date.Grade book is completely up-to-date.

Quick Review of last lectureQuick Review of last lecture New topics: Kingdoms Protista and New topics: Kingdoms Protista and

FungiFungi One Minute paperOne Minute paper LabLab

Quick ReviewQuick Review

Ch 21: Ch 21: Viruses/Bacteria/ArchViruses/Bacteria/Arch

aeaaea

Part I: VirusesPart I: Viruses

Viruses are non-cellularViruses are non-cellular Viruses are not living organismsViruses are not living organisms Require a host for reproduction and Require a host for reproduction and

maintenance (obligate intracellular maintenance (obligate intracellular parasites)parasites)

All viruses have at least 2 parts: a All viruses have at least 2 parts: a protein capsid and an inner core of protein capsid and an inner core of nucleic acid (either DNA or RNA)nucleic acid (either DNA or RNA)

Part I: VirusesPart I: VirusesViral

Reproduction I

Bacteriophages are viruses that infect bacteria. They reproduce by:

a) Lytic cycle

b) Lysogenic cycle


Viral Reproduction II

Animal viruses use cell membranes as camouflage. New viruses are released by budding.

Part II: ProkaryotesPart II: Prokaryotes

Both Bacteria and Archaea are Both Bacteria and Archaea are prokaryotesprokaryotes

Prokaryotes lack a nucleus and most Prokaryotes lack a nucleus and most other organelles found in eukaryotic cellsother organelles found in eukaryotic cells

Prokaryotes reproduce asexually by Prokaryotes reproduce asexually by binary fissionbinary fission

Genetic variation occurs mainly by Genetic variation occurs mainly by mutations, but also through conjugation, mutations, but also through conjugation, transformation and transduction.transformation and transduction.


flagella


Reproduction– binary fission (aka cloning, Reproduction– binary fission (aka cloning, 1 splitting into 2, etc.)1 splitting into 2, etc.)

Reproduction can occur as often as every Reproduction can occur as often as every 12 minutes in the right conditions. 12 minutes in the right conditions.

Because reproduction is so quick, more Because reproduction is so quick, more genetic mutations (mistakes) are made.genetic mutations (mistakes) are made.

Haploid (1 copy) so genetic mutations are Haploid (1 copy) so genetic mutations are subjected to natural selection immediatelysubjected to natural selection immediately

Part II: ProkaryotesPart II: ProkaryotesOnly 1

chromosome

That’s NOT the only

DNA found in bacteria. They also have very

small pieces of circular

DNA free in the cell, called

plasmids. Genes for antibiotic resistance are usually found on plasmids.


Reproduction is asexual, but 3 methods of Reproduction is asexual, but 3 methods of genetic recombination exist.genetic recombination exist. 1. conjugation-one bacterium passes DNA 1. conjugation-one bacterium passes DNA

through sex pilus to a 2through sex pilus to a 2ndnd bacterium bacterium 2. transformation-bacterium picks up free 2. transformation-bacterium picks up free

pieces of DNA from environmentpieces of DNA from environment 3. transduction-bacteriophages pass small 3. transduction-bacteriophages pass small

pieces of bacterial DNApieces of bacterial DNA

Note: plasmids can be passed from one Note: plasmids can be passed from one bacterium to another by any of these means.bacterium to another by any of these means.


Prokaryotes can survive very harsh Prokaryotes can survive very harsh conditions by forming spores.conditions by forming spores.

Cell dehydrates, leaving only a small Cell dehydrates, leaving only a small portion of cytoplasm and the portion of cytoplasm and the chromosome surrounded by 3 thick chromosome surrounded by 3 thick layers of spore coat.layers of spore coat.

Can survive desert heat, arctic ice, Can survive desert heat, arctic ice, boiling water, and time—thousands of boiling water, and time—thousands of years!years!


Oxygen requirementsOxygen requirements Most prokaryotes require oxygen to Most prokaryotes require oxygen to

survivesurvive Obligate aerobesObligate aerobes

Some can live with or without oxygenSome can live with or without oxygen Facultative anaerobesFacultative anaerobes

Some are poisoned by oxygenSome are poisoned by oxygen Obligate anaerobes Obligate anaerobes


Bacteria are usually discussed Bacteria are usually discussed concerning infections, but they serve concerning infections, but they serve some very useful purposes.some very useful purposes.

Some are photosynthetic, producing Some are photosynthetic, producing oxygen.oxygen.

Some are useful for decomposition.Some are useful for decomposition. Some aid in digestion.Some aid in digestion. Nitrogen-fixation in plant root nodules.Nitrogen-fixation in plant root nodules.

Part II: ProkaryotesPart II: Prokaryotes Archaea are discussed in terms of their Archaea are discussed in terms of their

unique habits.unique habits. Methanogens live in anaerobic Methanogens live in anaerobic

environments (swamps, intestinal tracts) environments (swamps, intestinal tracts) and produce methane gasand produce methane gas

Halophiles live in extremely salty Halophiles live in extremely salty environmentsenvironments

Thermoacidophiles live in extremely hot, Thermoacidophiles live in extremely hot, acidic environments (geysers, hot springs, acidic environments (geysers, hot springs, thermal vents, around volcanoes)thermal vents, around volcanoes)

Believe it or not! Archaea are genetically Believe it or not! Archaea are genetically more similar to eukaryotes than bacteria!more similar to eukaryotes than bacteria!

Any Questions?Any Questions?

Let’s move on to today’s topics:Let’s move on to today’s topics: Ch22: Kingdom ProtistaCh22: Kingdom Protista Ch23: Kingdom FungiCh23: Kingdom Fungi

Kingdom ProtistaKingdom Protista

Believed to have evolved as the first Believed to have evolved as the first eukaryotes.eukaryotes.

Organisms in this group just don’t fit perfectly Organisms in this group just don’t fit perfectly into any other Kingdom in the Domain Eukarya.into any other Kingdom in the Domain Eukarya.

Most protists are unicellular.Most protists are unicellular. Asexual reproduction is common, but sexual Asexual reproduction is common, but sexual

reproduction also occurs.reproduction also occurs. Most diverse group of organisms of any Most diverse group of organisms of any

kingdom.kingdom.

Endosymbiotic hypothesisEndosymbiotic hypothesis

Protists are believe to be the oldest eukaryotes on the evolutionary tree.

Diversity of ProtistsDiversity of Protists

It is hard to classify protists into It is hard to classify protists into categories, because they are so categories, because they are so diverse as a group.diverse as a group.

Protists include: algaes, amoebas, Protists include: algaes, amoebas, single-celled swimmers, plankton, single-celled swimmers, plankton, plant-like organisms, molds, etc.plant-like organisms, molds, etc.

Phylum Chlorophyta: green Phylum Chlorophyta: green algaealgae

Life Cycle of Chlamydomonas, a unicellular green algae

Zygote is the only diploid part of the life cycle.


Spirogyra is a filamentous green algae. They form end-to-end chains of cells. Often found on the surfaces of ponds.

Conjugation -


Multicellular green algae

Chara is a stonewort, the type of green algae believed to be most closely related

to plants.


Volvox is a colonial green alga.

Phylum Rhodophyta: red Phylum Rhodophyta: red algaealgae

Commercial importance of red algae:

Agar

Carrageen

Porphyra

Phylum Phaeophyta: brown Phylum Phaeophyta: brown algaealgae

Underwater forests-

Kelp-

Pectin-

Phylum Bacilariophyta: the Phylum Bacilariophyta: the diatomsdiatoms

Silica-

Diatomaceous earth-

Plankton-

Reproduction-

Phylum Pyrrophyta: the Phylum Pyrrophyta: the dinoflagellatesdinoflagellates

Some are photyosynthetic

Symbiotic

Parasitic

Red tide-

Need a break?Need a break?

Thanks for your attention!Thanks for your attention! Take 10 minutes.Take 10 minutes.

What’s next?What’s next? More protistsMore protists Kingdom FungiKingdom Fungi

Phylum EuglenophytaPhylum Euglenophyta

Freshwater

Typical of difficulties in categorization of protists: 1/3 have chloroplasts, the other 2/3 do not.

No sexual reproduction. Longitudinal fission.

Phylum Zoomastigophora: Phylum Zoomastigophora: the zooflagellatesthe zooflagellates

Trypanosomes- transmitted by the bite of a tsetse fly,

cause African Sleeping Sickness.

Phylum Zoomastigophora: Phylum Zoomastigophora: the zooflagellatesthe zooflagellates

Giardia Lamblia

Attaches to intestinal tract.

Other zooflagellates are known to spread sexually by infecting the vagina and urethra of women, and the prostate, seminal vesicles and urethra of men.

Protists with pseudopodsProtists with pseudopodsPhylum Rhizopoda- amoebas, including Entamoeba hystolytica

Phylum Foraminifera- calcium carbonate shell

Phylum Actinopoda-radiolarians

Trivia-

White Cliffs of Dover, Egyptian pyramids, oil deposits

Phylum Ciliophora: the Phylum Ciliophora: the ciliatesciliates

Very diverse group; very complex single-celled organisms with specialized regions to carry out various functions.

Phylum Apicomplexa: the Phylum Apicomplexa: the sporozoanssporozoans

Life cycle of

Plasmodium vivax,

the organism

that causes malaria.

Slime molds and water Slime molds and water moldsmolds

Phyla Myxomycota, Acrasiomycot

a and Oomycota

Kingdom FungiKingdom Fungi

Multicellular eukaryotesMulticellular eukaryotes External digestionExternal digestion Most are saprotrophic decomposersMost are saprotrophic decomposers Some are parasiticSome are parasitic Several fungi form symbiotic Several fungi form symbiotic

relationships with plants or algaerelationships with plants or algae Cell walls have chitin, not celluloseCell walls have chitin, not cellulose Not photosyntheticNot photosynthetic Reproduce by sporesReproduce by spores

Network of hyphae

Fungal reproduction involves spores.

Network of hyphae

Kingdom FungiKingdom Fungi

Phylum Zygomycota: zygospore fungiPhylum Zygomycota: zygospore fungi 665 species665 species

Phylum Ascomycota: sac fungiPhylum Ascomycota: sac fungi 30,000 species30,000 species

Phylum Basidiomycota: club fungiPhylum Basidiomycota: club fungi 16,000 species16,000 species

Phylum Deuteromycota: imperfect fungi Phylum Deuteromycota: imperfect fungi (i.e., means of sexual reproduction not (i.e., means of sexual reproduction not known)known) 17,000 species17,000 species

Phylum ZygomycotaPhylum Zygomycota

Black bread mold: Rhizopus stolonifer

Phylum Ascomycota: sac Phylum Ascomycota: sac fungifungi

Yeast-

Phylum Basidiomycota: club Phylum Basidiomycota: club fungifungi

Phylum DeuteromycotaPhylum Deuteromycota

Penicillium

Organisms from this phylum are both very helpful (penicillin from Penicillium, soy sauce and citric acid from Aspergillus) and very harmful (Aspergillus can be toxic if inhaled; athlete’s foot; ringworm; Candida albicans causes vaginal yeast infections)

Symbiotic relationshipsSymbiotic relationships

mycorrhizas

lichens

Deadly FungiDeadly Fungi Amanitas Amanitas is a group of mushrooms that causes is a group of mushrooms that causes

symptoms similar to acute alcohol intoxication. 1-6 hrs, symptoms similar to acute alcohol intoxication. 1-6 hrs, victim staggers, loses consciousness, hallucinates, victim staggers, loses consciousness, hallucinates, usually vomits before enough enters the bloodstream to usually vomits before enough enters the bloodstream to be toxic.be toxic.

Amanitas phalloidesAmanitas phalloides is known as the “Death Angel” is known as the “Death Angel” mushroom—accounts for over 90% of fatalities from mushroom—accounts for over 90% of fatalities from mushroom poisoning. Symptoms usually don’t begin mushroom poisoning. Symptoms usually don’t begin until 10-12 hrs later. Poison interferes with RNA until 10-12 hrs later. Poison interferes with RNA transcription—victim dies from liver and kidney damage.transcription—victim dies from liver and kidney damage.

Psilocybe mixicanaPsilocybe mixicana contains a chemical called contains a chemical called psilocybin-acts like LSD. Produces a dream-like state, psilocybin-acts like LSD. Produces a dream-like state, visions of colorful patterns, sharp senses.visions of colorful patterns, sharp senses.

Claviceps purpureaClaviceps purpurea- ergot fungus, infects rye, ground up - ergot fungus, infects rye, ground up with rye to make bread. Causes vomiting, feelings of with rye to make bread. Causes vomiting, feelings of intense heat or cold, muscle pain, yellow face, lesions intense heat or cold, muscle pain, yellow face, lesions on hands & feet, hysteria & hallucinations. Ergot on hands & feet, hysteria & hallucinations. Ergot contains lysergic acid, from which LSD can easily be contains lysergic acid, from which LSD can easily be made. Salem Witch Trials!!made. Salem Witch Trials!!

Need a break?Need a break?

Thanks for your attention!Thanks for your attention! Take 10 minutes.Take 10 minutes.

What’s next?What’s next? 1-minute paper1-minute paper LabLab

Overview of today’s labOverview of today’s lab

Gram StainingGram Staining

Let’s read p73-74 together (lab Let’s read p73-74 together (lab manual)manual)

Preparation for Thursday, Mar Preparation for Thursday, Mar 1010

Read chapter summaries for Ch 24-28 Read chapter summaries for Ch 24-28 (Plants)(Plants)

Folder Review #7Folder Review #7 should include “one-minute papers” from should include “one-minute papers” from

Mar 8 & 10; one article review; and lab Mar 8 & 10; one article review; and lab summary & data from Mar 8 & 10summary & data from Mar 8 & 10

Be ready for study sessionBe ready for study session Make a list of your questionsMake a list of your questions

Tuesday March 8, 2005 BIOL L100 Indiana University Southeast David Partin, Instructor.

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