What is the primary role of organotrophic bacteria in ecosystems?

Associations between two organisms which benefit each of them are:

All of the following groups of microorganisms would be found below the surface of a Winogradsky column EXCEPT:

Viable counting methods provide an inaccurate picture of the number of microbes in a natural sample because:

Which of the following can be used to estimate phytoplankton biomass in natural samples?

If two isotopic forms of an element are available, enzymes are more likely to react with molecules that contain the

Rank the following aquatic habitats in order of INCREASING rates of primary production.

1. lakes

2. open ocean

3. areas of upwelling in ocean

The major factor(s) affecting microbial activity in soil is the availability of

The energy source which drives the hydrothermal vent ecosystem

Which of the following compounds are important substrates for methanogenic bacteria in natural environments?

Much of the H2 used by methanogens in anaerobic environments is produced by bacteria which metabolize

All of the following are important groups of microbes in the rumen EXCEPT:

The formation of nitrogen gas from nitrate by microorganisms is called

All of the following are NOT susceptible to microbial degradation EXCEPT:

In both Agrobacterium and Rhizobium, genetic information required for association with plants is contained on