Exam 21: Decomposition and Nutrient Cycling

In an estuary, the zone of maximum vertical difference in density of water layers is called the

The rate of nutrient cycling in an ecosystem depends on the rates of two key processes: primary productivity and ________.

The rate of decomposition is faster for proteins, simple sugars, cellulose, and hemicellulose than it is for lignin.

Which of the following breaks down the slowest during decomposition?

Fungi are the dominant decomposers of dead animal matter, whereas bacteria are the dominant decomposers of dead plant matter.

Aquatic arthropods that fragment organic particles and also eat bacteria and fungi on the surface of the litter are called

Bacteria, fungi, and animals are all important in decomposition.

The release of organically bound nutrients into an inorganic form is called immobilization.

In plants, the absorption of a portion of nutrients from senescing tissues in order to use the nutrients for production of new tissues is called

In a process known as the ________, the rise and fall of water depth with tidal cycles brings nutrients into coastal marshes from coastal ocean waters.

The release of organically bound nutrients into an inorganic form is called ________.

Decomposers obtain their energy by photosynthesis.

In open water, the undissolved remains of dead organisms and other organic material that drifts toward the bottom are called ________ organic matter.

Roots can alter the chemical environment of the rhizosphere by exuding

All heterotrophs function, to some degree, as decomposers.

The physical fragmentation of organic matter into smaller pieces is achieved primarily by invertebrate detritivores.

During the process of decomposition, carbon quality typically declines.

________ is the process by which plants absorb a portion of their nutrients from senescing tissues to be stored and used for the production of new tissues.

In open-water ecosystems, turnover prevents the movement of nutrients between the bottom and surface layers.

Most of the nutrients in the leaves of a deciduous plant are lost when the leaves senesce and drop to the ground.