Chapter 4 Homework 1 The DNA of archaeons is complexed with histones suggesting a Archaeons are more closely related to eukarya than bacteria 2 One characteristic of Achaea that is unique to the domain is a The chemistry of the archaeal cytoplasmic membrane 3 Would most archaea stain Gram positive or Gram negative a Gram negative because their cell walls would likely not retain the crystal violet mordant complex 4 Would you expect to find methanogens and halophiles in the same environment a No because methanogens would not likely survive the stressful osmotic conditions where halophiles are found 5 All archaea are extremophiles a False a True a 6 The biggest physiological challenge for halophiles is avoiding osmotic shock 7 Is penicillin effective against archaeons and bacteria Explain Penicillin is not effective against archaeons Even though the cell walls of archaeons involve linkage between wall peptides similar to what occurs in bacteria these wall peptides contain only L amino acids Penicillin is effective against bacteria because its structure is similar to the D alanine D alanine peptide bond found exclusively in bacteria 8 The two major phyla of the Archaea are the a Euryarchaeota and Crenarchaeota 9 Select the incorrect statement a Barophiles are organisms that grow under extreme pH conditions 10 rRNA is a good molecule to generate phylogenetic relationships among species because a it is found in all known cells 11 A characteristic that is unique to the domain Archaea is a A cell membrane constructed from unique lipids 12 Archaea are thought by many to be descended from the first life forms because a The first identified Archaea were extremophiles making them well suited for the conditions on Earth when life arose 13 Unlike bacteria the cytoplasmic membrane of archaea a Can exist as a monolayer 14 Which of the following is a structural adaptation for life at high temperatures a Lipid monolayers instead of bilayers ether linkages instead of ester linkages and isoprenoids instead of fatty acids 15 All methanogens are anerobic a True
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