The Diatom Asterinonella Excludes the Diatom Cyclotella in Laboratory Experimental

question 13

Multiple Choice

The diatom Asterinonella excludes the diatom Cyclotella in laboratory experimental cultures when phosphate concentrations are low.But,Cyclotella excludes Asterionella when silicate supplies are low.However,when there are balanced supplies of silicate and phosphorus,the two diatoms coexist.This is explained by

• A) There being a fundamental niche for both species when each is provided sufficient concentrations of a resource on which they are inferior.
• B) There being niche complementarity for both species when each is provided an abundance of a resource.
• C) There being no fundamental or realized niche for either species.
• D) There being a realized niche for both species when each is provided sufficient concentrations of a resource on which they are inferior.

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Definitions:

Costs Per Equivalent Unit

A calculation used in process costing that distributes costs evenly across units produced, factoring in various stages of completion.

Weighted-Average Method

An inventory costing method that assigns cost to inventory on the basis of the average cost of all similar goods available during the period.

Equivalent Units of Production

A conversion of partially completed units into a number of fully completed units during a period, used in process costing systems.

Costs Per Equivalent Unit

A calculation used in process costing that determines the cost of a single completed unit, considering work done on partial units.