Four of the Five Statements Below Apply to the Phosphorus

question 53

Multiple Choice

Four of the five statements below apply to the phosphorus cycle. Which one does not apply?

• A) Phosphorus cycles from land to water and back again.
• B) Phosphorus does not exist in a gaseous state.
• C) Dissolved phosphorus enters aquatic ecosystems from the atmosphere.
• D) Phosphorus will probably be depleted during the 21st century.
• E) Erosion from clear-cutting and agriculture accelerate phosphorus loss.

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Definitions:

Transcriptionally Inactive

Describes genes or segments of DNA that are not being transcribed into RNA.

Constitutive Genes

Genes that are continuously expressed under normal cellular conditions, providing the basic functions necessary for the cell's survival.

Housekeeping Genes

Genes that are constantly expressed to maintain basic cellular function; they are essential for the maintenance of normal cellular activities.

Alternatively Spliced

Refers to the process by which different combinations of exons are joined or spliced together, resulting in multiple mRNA variants from a single gene.