The modern oceans are a major repository for the greenhouse gas ________,which some organisms utilize to make their shells.
A)SiO2
B)Ammonia
C)Limestone
D)CO2
E)Iron oxide

Question

Quizplus · Accepted Answer

The greenhouse gas that is a major repository in modern oceans is carbon dioxide (CO2). Some organisms, such as phytoplankton and mollusks, utilize CO2 to make their shells, which can eventually become part of sedimentary rock formations such as limestone.

The Modern Oceans Are a Major Repository for the Greenhouse