What method would you use to identify nitrogen from biogenic origins in a sample from coastal waters?

When measuring microbial community metabolic activity, __________ is always necessary.

Why would it be an advantage for a primitive eukaryotic cell to form a mutualistic relationship with a prokaryote capable of aerobic cellular respiration?

A mutant of Rhizobium leguminosarum (a bacterium) is able to survive and reproduce in the laboratory outside of plant roots, but can no longer initiate root nodule formation. What type of genes are most likely mutated in this mutant?

What method would you use to identify nitrogen from biogenic origins in a sample from coastal waters?

You want to know if a specific species of coliform bacteria is present in a water sample from a lake. Which of the following would you use?

The earliest stromatolites were probably formed by

________ is a term used to describe dead organic matter.

Which of the following methods would you use to find out how much carbon dioxide is being produced by microbes in a given ecosystem if you cannot grow them in cultures?  

What is the largest carbon reservoir on Earth?