Fill in the blank with the appropriate word or phrase. 

1.  Extremely ________________ Archaea are a diverse group of prokaryotes that inhabit highly saline environments.

2.  A Gram stain of Halobacterium would show a Gram _____________ cell.

3.  Bacteria that produce methane are called ______________.

4.  __________ is an example of a thermophillic, cell wall-less Archaea.

5.  Those microorganisms with growth temperature optima over 80°C. are called ______________.

6.  Archaeoglobus couples the oxidation of H2, lactate, pyruvate, glucose, or complex organic compounds to the reduction of ____________ to sulfide.

7.  In terrestrial environments, sulfur rich springs that consist of boiling mud and soils, and are mildly to extremely acidic because of biological production of sulfuric acid, are called _____________.

8.  ___________ is, at present, the most thermophillic of all known organisms.

9.  Thermosome is a member of a class of proteins known as _______________.

10.  ______________ is a molecule used by some hyperthermophilic methanogens to increase cytoplasmic ionic strength, and thereby, increasing melting temperature of DNA.

11. All halophilic Archaea stain gram ______, reproduce by ______ and _______ (do / donot) form resting stages or spores.

12. One distinguishing characteristic that Thermoplasma (Archaea) and the mycoplasmas (Bacteria) have in common is __________

13. Compounds within thecell that counteract the tendency of the cell to become dehydrated under conditions of high osmotic strength are known as ___________

14.______________ is a light driven pump present in halobacteria to pump Cl- into the cell as an anion for K+

15. The membrane of Thermoplasma consists of a lipid with ______ and _________ subunits

16. Euryarchaeota whose optimal growth temperature is over 80 oC are called _____________.

17. Hot, generally acidic, sulfur-rich, terrestrial environments are called _____________.

18. Proteins, called ________________ function to re-fold partially denatured proteins. The amount of this ________ (increases / decreases) dramatically near the cell's grwth temperature limit.

19. The topoisomearse ______________ introduces Positive supercoils in DNA and this greatly stabilises DNA to heat denaturation.