Midterm exam #2 - MB 409 - Spring 2003 Name _________Key_______

1. What are the three primary evolutionary branches of life? (5 points)

  1. Bacteria
  2. Archaea
  3. Eukarya

2. ___A__Which is not a method used by Bacteria to fix carbon: (3 points)
A. reverse electron flow
B. the Calvin cycle
C. the hydroxypropionate pathway
D. the reverse TCA cycle

3. ___B__ Taq polymerase used in PCR amplification is a DNA polymerase from _______ aquaticus: (3 points)
A. Trichomonas
B. Thermus
C. Treponema
D. Tetrahymena

4. ___D__ Gliding motility is based (at least where the mechanism is known) on the secretion of: (3 points)
A. polyaromatic hydrocarbons
B. protons
D. polysaccharide
E. carbon dioxide

5. ___C__ The heterocysts of filamentous cyanobacteria carrry out what process? (3 points)
A. oxygenic photosynthesis
B. photorespiration
C. nitrogen fixation
D. reverse electron flow

6. ___A__ What is the defining characteristic of the Gram-positive cell envelop? (3 points)
A. the absence an outer membrane
B. the thick layer of peptidoglycan
C. the periplasm
D. glycerol ethers

7. ___D__ Which of the following is not an issue that has to be dealt with for thermophilic growth? (3 points)
A. nucleic acid denaturation
B. protein denaturation
C. instability of some small molecules
D. low rates of diffusion
E. racemization of amino acids

8. ___E__ The three major methods of sulfur metabolism are: (3 points)
A. sulfur fermentation, thiolation, and decarboxylation
B. sulfur amidation, phosphorylation, and disproportionation
C. sulfur acidification, hydroxylation, and protonation
D. sulfur kination, carbonylation, and transamidation
E. sulfur oxidation, reduction, and respiration

9. ___C__ The electron transport chain is driven by... (3 points)
A. substrate-level phosphorylation
B. the TCA cycle
C. oxidation/reduction reactions
D. the dark reactions of photosynthesis

10. ___B__ RNase polymerase in Archaea resembles... (3 points)
A. bacterial RNA polymerase
B. RNA polymerase II in eukaryotes
C. T7 RNA polymerase
D. reverse transcriptase

11. ___A__ Archaeal membrane lipids are... (3 points)
A. glycerol ethers of 20 or 30 carbon isoprenyl alcohols
B. glycerol esters of 12-24 carbon fatty acids
C. sterols and fatty acids
D. polyaromatic hydrocarbons
E. Archaea do not have membrane lipids

12. List the three major possibilities for the origin of viruses (5 points)

  1. Degenerate cellular parasites
  2. genetic offshoots of their hosts
  3. leftovers of the precellular life

13. Describe the two fundamentally different types of thermophiles. (5 points)

Ancestral thermophiles are thermophilic organisms that apparently only have thermophilic ancestors (at least back to the last common ancestor). These organisms have not adapted to life a high temperature because they have always been there.

Adaptive (recent) thermophiles are thermophilic organisms with mesophilic ancestry. The ancestors of these organisms presumably adapted to life at low temperature long ago, then readapted to life at high temperatures more recently.

14. Tell me in a sentence about something interesting you learned from the paper by John Reeve, "Archaebacteria then...Archaes now (Are there really no archaeal pathogens?)", other than the fact that there are no known archaeal pathogens or that the first archaeal genes were cloned by complementation of E. coli auxotrophs. (5 points)

e.g. Archaea have histones, and package their DNA in nucleosomes like those of eukaryotes.

15. Describe (include a diagram) one bacterial life/developmental cycle (10 points).

e.g. Myxxococcus. They grow individually in rich environments, but when starved, aggregate into 'slugs' than move as a single organism. The cells in the slug differentiate into fruiting bodies, with base, stalk, sporangium, and spores cells. Spores are released into the wind, & those that land in a better environment germinate to produce a new crop of free-living cells.

16. List 15 of the major evolutionary branches of Bacteria. Some of these will, of course, need to be groups that are mostly or entirely known only from rRNA sequences rather than cultivated species. (1 point each - 15 points total)

  1. Aquifex & relatives
  2. Thermotoga & relatives
  3. Green non-sulfur Bacteria
  4. Deinococci
  5. spirochaetes
  6. green sulfur Bacteria
  7. Bacteroids/Flavobacteria
  8. Planctomycetes
  9. Chlamydia
  10. Gram positive Bacteria
  11. Cyanobacteria
  12. Purple Bacteria
  13. Acidobacterium & relatives
  14. OP11 & relatives
  15. Verrucomicrobium & relatives

17. List the two major branches of Archaea. (5 points)

  1. Crenarchaea
  2. Euryarchaea

18. Give one genus that possesses the phenotypic traits indicated. Choose 20 of these traits to answer - mark out the 4 you choose not to answer. A list of genera from the class notes is given at the end of this test for your reference. (1 point each for a total of 20 points)

(examples)

________________Beggiatoa___________________ chemoautotrophic

________________Nostoc___________________ oxygenic photosynthesis

________________Rhodospirillum___________________ anoxygenic photosynthesis

________________Thermus___________________ thermophilic

________________Herpetosiphon___________________ filamentous

________________Planctomyces___________________ budding division

________________Escherichia___________________ rod-shaped

________________Methanobacterium___________________ methanogenic

________________Sulfolobus___________________ sulfur respiration

________________Thermoproteus___________________ sulfur reduction

________________Chromatium___________________ sulfur oxidation

________________Cytophaga___________________ gliding motility

________________Escherichia___________________ flagella

________________Haloarcula___________________ gas vacuoles

________________Treponema___________________ spirochaete

________________Rhodospirillum___________________ spirillum

________________Sulfolobus___________________ acidophilic

________________Halobacterium___________________ halophilic

________________Mycoplasma___________________ obligate parasite

________________Bacillus___________________ Gram positive cell envelop

________________X___________________ appendaged

________________X___________________ fibrous stalk

________________X___________________ internal membranes

________________X___________________ anaerobic & eukaryotic


NCSU Honor Pledge:

I have neither given nor received unauthorized aid on this test.

Sign ______________Key_____________________ Date ____3/24/04___________


Acanthamoeba
Acetobacterium
Acidianus
Acidobacterium
Agrobacterium
Anabaena
Anaerolinea
Aquaspirillum
Aquifex
Archaeoglobus
Arthrobacter
Bacillus
Bacteroides
Balnearium
Barbulanympha
Bdellovibrio
Beggiotoa
Borrelia
Brachyspira
Bradyrhizobium
Brevinema
Caldilinea
Caldotoga
Campylobacter
Caulobacter
Chlamydia
Chlamydiophila
Chlamydomonas
Chlorobaculum
Chlorobium
Chloroflexus
Chloroherpeton
Chloronema
Chlorothrix
Chromatium
Citrobacter
Clathrochloris
Clostridium
Coprothermobacter
Corynebacterium
Cytophaga
Dehalococcoides
Deinococcus
Desulforobacterium
Desulfovibrio
Desulfurococcus
Desulfurolobus
Dictyoglomus
Dictyostellium
Enterobacter
Enterococcus
Erwinia
Escherichia
Eubacterium
Euglena
Fervidobacterium
Fibrobacter
Flavobacterium
Flexistipes
Frankia
Fritschea
Fusobacterium
Gemmata
Geothrix
Geotoga
Giardia
Haloarcula
Halobacterium
Helicobacter
Heliobacterium
Heliothrix
Herpetosiphon
Holophaga
Hydrogenivirga
Hydrogenobacter
Hydrogenobaculum
Hydrogenothermus
Isosphaera
Klebsiella
Kouleothrix
Lactobacillus
Leptonema
Leptospira
Leuconostoc
Listeria
Marinithermus
Marinotoga
Meiothermus
Metallosphaera
Methanobacterium
Methanococccus
Methanomicrobium
Methanopyrus
Methanosarcina
Micrococcus
Mycobacterium
Mycoplasma
Myxococcus
Natronobacterium
Neochlamydia
Niesseria
Nitrobacter
Nitrospira
Nocardia
Nostoc
Oceanothermus
Oscillochloris
Parachlamydia
Paramecium
Pelodictyon
Persephonella
Pfisteria
Pirellula
Planctomyces
Plasmodium
Prochloron
Prosthecobacter
Prosthecochloris
Proteus
Pseudomonas
Pyrobaculum
Pyrococcus
Pyrodictium
Rhizobium
Rhodobacter
Rhodocyclus
Rhodomicrobium
Rhodopseudomonas
Rhodospirillum
Rickettsia
Roseiflexus
Saccharomyces
Salmonella
Shigella
Simkania
Sphaerobacter
Spirochaeta
Spirogyra
Spironema
Sporomusa
Staphylococcus
Staphylothermus
Stella
Streptococcus
Streptomyces
Stygiolobus
Sulfolobus
Sulfurihydrogenobium
Synergistis
Thermococcus
Thermocrinus
Thermodesulfobacterium
Thermodiscus
Thermofilum
Thermomicrobium
Thermopallium
Thermoplasma
Thermoproteus
Thermosipho
Thermotoga
Thermovibrio
Thermus
Thiobacillus
Treponema
Trichomonas
Trypanosoma
Ultramicrobacteria
Verrucomicrobium
Vulcanithermus
Waddlia
Yersinia