Exam 31: Microorganisms in Terrestrial Ecosystems

One of the more important genera of gram-positive aerobic actinomycetes found in soils is ________.

A common resident of the rhizosphere that can enhance plant growth is ________.

Soil protists often utilize bacteria as a nutrient source.

The region of soil in the immediate vicinity of the roots of plants is called the ________.

Actinorrhizae can benefit the plant by providing it with the products of ________.

Most organic matter found in soils results from primary producers such as ________.

The surface of a plant root is called the __________. or

When rhizobia approach a plant root,the plant initially responds by

Mycorrhizal fungi can either be intracellular or extracellular.

Microorganisms in soil are located in thin water films on particle surfaces where oxygen is present at high levels.

Lignin degradation by basidiomycetes is an aerobic process that is catalyzed by phenoloxidases.

The ____________ mycorrhizae are the most common type of mycorrhizae.

Microbes that live on the surface of plants are called __________ . or

Which organism was responsible for the Irish Potato Famine?

An average gram of forest soil contains about

Enzymes,once released from plant and animal cells,can remain present and function independent of the organisms that synthesized them.

The common building block of ___________ is the phenylpropene unit,which consists of a hydroxylated six-carbon aromatic benzene ring and a three-carbon linear side chain. or

Legume plants provide certain amino acids to the ___________ so that they do not need to assimilate ___________.In return,the bacteroids shuttle amino acids bearing the fixed nitrogen back to the plant.

Fungi can be present at up to several hundred meters of hyphae per gram of soil.

Recent studies indicate that active prokaryotic assemblages are present in high-temperature oil reservoirs,including genera such as