Typical electron donors used by dissimilative sulfate-reducers are
A) hydrogen, water, and hyrdrogen sulfide. B) hydrogen, lactate, and pyruvate. C) carbon dioxide, hydrogen, and water. D) sulfate, sulfur, and thiosulfate.
The phylogenetic trees of the nifH and SSU rRNA genes of nitrogen-fixing bacteria are incongruent because
A) nitrogenase is an anaerobic enzyme. B) this is a characteristic of all enzyme genes. C) of horizontal gene transfer. D) very few microbes have the nifH gene.
Microbial diversity is thought of in terms of phylogenetic diversity and functional diversity because
A) similar functional traits are often found in divergent phylogenetic groups. B) phylogenetic diversity dictates functional diversity in microbes. C) functional diversity only pertains to functions that are not phylogenetic. D) similar phylogenetic groups almost always have similar functional traits.