Biology Exam IV

Final: Monday, 12/975% new material

25% old

Self quizes

• 22 evolution• 27 Bacteria 27• 28 protist• 31 fungi• viruses

Viruses

Horizontal transmission of a plant viral disease could be caused by

Insects as vectors carrying virus particles between plants

RNA viruses require their own supply of certain enzymes because

Host cells do not have enzymes available that can replicate the viral genome

R plasmidContains genes for antibiotic resistance and for sex pili

Transposition differs from other mechanisms of genetic recombination because itScatters genes to new loci in the genome

An operon codes for an amino acid. If the regulation of this operon is like that of the trp operon

The amino acid acts as a corepressor

A mutation that makes the regulatory gene of an inducible operon nonfunction would result in

Continuous transcription of the operon’s genes

Which information transfer is catalyzed by reverse transcriptase?

RNA -> DNA

Which characteristic is common to BOTH bacteria and viruses?Nucleic acid as genetic material

Which of the following processes would never contribute to genetic variation within a bacterial population?

meiosis

During conjugation between an Hfr cell and an F- cell

Genes from the Hfr cell may replace the genes of the F- cell by recombination

Emerging viruses arrive by

All of the above

a) Mutation of existing virusesb) The spread of existing viruses to

new host speciesc) Broader dissemination of an

existing virus within the current host population

A certain mutation in E coli makes the lac operator unable to bind to the active repressor. How would this affect the cell?The cell would wastefully produce the enzymes for lactose metabolism continuously, even in the absence of lactose

Gram-negative

• meningococcal menintus

• Thin cell wall• outer wall (OM): toxic

to humans• sensitive to osmotic

pressure• antibiotic tolerant• thin peptidoglycan layer

Gram-positive

• THICK peptidoglycan layer

• resistant to osmotic pressure

Classify bacteria by habitat

1. halophile2. coliform: your

digestive tract3. thermophile4. acidophile

Classify bacteria by metabolic pathway

1. obligate aerobe: require O2

2. anaerobe: O2 kills anaerobes

3. facultative aerobe: can live with O2 and not

4. heterotroph v photoautotroph

Classify bacteria by metabolic pathway

• M. tuber 1. obligate aerobe: require O2

Classify bacteria by metabolic pathway

• Cl. tetanic 2. anaerobe

Classify bacteria by metabolic pathway

• E. coli (facultative) 1. obligate aerobe: require O2

2. anaerobe: O2 kills anaerobes

3. facultative aerobe: can live with O2 and not

Classify bacteria by metabolic pathway

• cyanobacteria (photoautotroph)

1. obligate aerobe: require O2

2. anaerobe: O2 kills anaerobes

3. facultative aerobe: can live with O2 and not

4. heterotroph v photoautotroph

capsule: sugar material that covers cell wall

• Strep pyroxenes, H. influenza

• protect against phagocytosis

• protect against desiccation

• allow adherence

fimbriae & pili: attachment purpose structures

• pile: used for conjugation (sexual reproduction)

slime layer: sticky matrix of polysaccharides that protects the bacteria

• Streptococcus mutans cause tooth decays

taxis: movement toward or away from stimulus

internal/genome structure of bacteria

• one chromosome (DNA)• no organelles• plasma membrane

carries out metabolic processes

• Some bacteria have additional genomes, circular DNA, plasmids

binary fission: similar to mitosis

• one bacteria splits to two

• mitosis: split nucleus

endospore

• anthrax (Bacillus anthracis)

endospore

• botulism

endospore

• tetanus

endospore

• gas gangrene (Clostridium perfringen)

classify bacteria via nutritional intake

1. photoautotrophy2. chemoautotrophy3. photoheterotrophy4. chemoheterotrophy

photoautotrophy

• energy from sunlight• carob from CO2

chemoautotrophy

• energy from inorganic molecules like sulfur

• carbon from CO2

photoheterotrophy

• carbon from organic sources (other organisms)

chemoheterotrophy

• energy and CO2 from organic sources

eubacteria aka “bacteria”

• cell wall made of peptidoglycan

Archaea

• cell wall made of pseudomurein

methanogen

• anaerobic Archae• remove excess

hydrogen, O2

symbiotic categories

1. mutualism2. commensalism3. parasitism

Genus of bacterial diseases!

1. Borelia2. Treponema3. Staphylococcus4. Mycobacterium5. Yersinia6. Neisseria

1. Lyme2. syphilis3. toxic shock (MRSA)4. tuberculosis5. plague6. gonorrhea

Lyme

• Borelia

syphilis

• Treponema

MRSA

• Staphylococcus

tuberculosis

• Mycobacterium

plague

1. Bubonic2. pneumonic

• Yersinia

gonorrhea

• Neisseria

exotoxin

• G positive

botulin

• exotoxin• Gram positive

tetanus

• exotoxin• Gram positive

endotoxin

• Gram negative• you get more sick• bacteria has outer

membrane

Gram-positive

• EXOtoxin

Gram-negative

• ENDOtoxin• have outer membrane

Gram

• exotoxin– made of G positive– botulin and tetanin are

examples– can elicit immune

response – can be vaccinated

against

• endotoxin– made of G-negative– made of outer

membrane (OM)– are released when

bacteria die– does NOT elicit an

immune response – you get more sick – vaccination is difficult

Chlamydomonas

• eyespot• pyrenoid• protist

Diatom

• protist

Algae

• photosynthetic protist

Protists

• Lecture: Thursday 11/21 • Cercozoans• Forams• Radiolarians• Amoeba– 4 clades

• Rhodophyta (red algae)• Chlorophyta (green

algae)• Lab 26: slime molds

Cerocozoans

• Amoeba-looking cells• Clade foraminiferans

(“forams”)• Feed by pseudopodia

Phylum: Forams

• shrimp • Porous, multi-chambered calcium carbonate shells called tests

• Pseudopodia extend through the pores

• ocean pH environmental problem: acidity dissolves tests

Forams (importance)

• layers of foram tests in marine sediments from limestone and oil deposits– Egyptian pyramids

• act as carbon reservoir• used by geologists to

locate oil reserves (oil explorer)

• used to determine age of rocks and pas climate

forams

• limestone cliff in Dover England

Kingdom: radiolarians

• have silica tests fused into one piece (like diatoms)

• pseudopodia are called axopodia, which radiate from central body

• only ONE clade

Kingdom: amoeba

• have lobe-shaped pseudopodia (false feet) rather than threadlike

• do not have tests and have no shape

• The Blob (film)

Four Clades of Amoeba

1. Gymnanoebas2. Entaamoeba3. plasmodial slime mold4. cellular slime mold

Gymnanoebas

1. Gymnanoebas2. Entaamoeba3. plasmodial slime mold4. cellular slime mold

• free living (not disease causing)

• found in damp, environmental conditions (in your guts, soil, bottom of lakes)

Entaamoeba

1. Gymnanoebas2. Entaamoeba3. plasmodial slime mold4. cellular slime mold

• generally parasitic – ex. Entaamoeba histolytica:

causes dysentery and organ damage

– Naegleria: cause fatal encephalitis• found in warm fresh waters in

southern states• infections occur via nose and in

summer months• very rare: you’re more likely to

win the lottery

– E. histolyta in stool: cyst, trophozoite

– N. fowleri in brain

plasmodial slime mold

1. Gymnanoebas2. Entaamoeba3. plasmodial slime

mold4. cellular slime mold

• spend most life cycle as a unicellular plasmodium

• made up of thousands of cells that fuse to ONE giant cell with many nuclei

• When stressed, plasmodium develop to sporangia and produce spores.

• Spores germinate into biflagellated cells, which act as gametes or as amoeboid cells.

• Syngamy of gametes produce new plasmodium.

plasmodial slime mold

1. Gymnanoebas2. Entaamoeba3. plasmodial slime mold4. cellular slime mold

• Life cycle1. fruiting body2. spores released3. signal: cells come

together and fuse4. form plasmodium

cellular slime mold

1. Gymnanoebas2. Entaamoeba3. plasmodial slime mold4. cellular slime mold

• cells do NOT fuse; but they act as one organism

• spends most life cycle as feeding individual protist cells

• form pseudopodia (slug) when food is depleted

• slug develops to fruiting body to produce spores

cellular slime mold

• life cycle– fruiting bodies– amoebas– signal: cells aggregate

and form plasmodium slime mold; they do NOT fuse

– they move as one

kingdom: Rhodophyta (red algae)

• phycoerythrin (red pigment) which allowed Rhodophyta to live in deeper waters

• Most are large and multi-cellular

• store sugar as floridean starch (glycogen) like humans

• found in tropical waters

kingdom: Rhodophyta (red algae)

• Uses– eaten as food – agar: food, petri dish– coralline algae secrete

shells of calcium carbonate, which form coral reefs. Algae are NOT coral. They are part of the ecosystem that supports corals.

kingdom: chlorophyta (green algae)

1. chlorophylls 2. charophyceans

• have chloroplasts– chlorophyll a and b– store sugar in the form

of starch– have accessory pigments

and stacked thylakoids

– ex. Volva– ulva (sea lettuce)– calberna (sea feather)

Slides: slime mold

1. endamoeba histolytica2. foraminisera3. trypanosome

gambienso nasco4. paramecium5. plasmodium6. radiolarian ooze

tropical pacific