When the cotyledons appear above the soil during germination is called

Answer Details

Germination is classified based on the fate of the cotyledons (seed leaves) relative to the soil surface. In epigeal germination, the hypocotyl elongates rapidly and arches upward, pulling the cotyledons above the soil. Once above ground, the cotyledons may photosynthesize briefly before the true leaves take over. Examples include beans (Phaseolus) and castor oil plant.

In hypogeal germination, the epicotyl elongates instead, pushing the plumule (young shoot) above the soil while the cotyledons remain buried underground. Maize and mango are common examples of hypogeal germination.

The prefix epi- means "above" and hypo- means "below," while -geal relates to the earth. This makes the terminology self-explanatory: epigeal means the cotyledons come above the earth, and hypogeal means they stay below.

Note that epicotyl and hypocotyl are parts of the embryonic axis, not types of germination. The epicotyl is the region above the cotyledon attachment point, and the hypocotyl is the region below it. The question asks about the type of germination, not a plant structure, so the correct answer is epigeal germination.