Lesson 6 ·Class 9 · Seeds — Structure and Germination · Sort Lab
Hypogeal vs Epigeal
Do the cotyledons come up, or stay down?
Sort each statement by the type of germination it describes.
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All items sorted — check each bin.
VS
Free play — sort every item into the bin it belongs in; each correct drop tells you why. Switch to when you're ready to test yourself.
The trick is which part elongates. hyPOcotyl lifts them UP (epigeal); ePIcotyl leaves them DOWN (hypogeal). The names cross over — that is exactly why it is examined.
What this lesson covers
Challenges to clear
- Sort every statement.
- Fill the Epigeal column — germination that lifts the cotyledons above the soil.
The task
Sort each statement by the type of germination it describes.
What this lesson covers
- Hypogeal — Cotyledons stay below: Cotyledons remain under the soil (Hypo- means below, geo- means earth.); The epicotyl elongates and arches upward (The part ABOVE the cotyledons grows, leaving them behind.); Gram, pea and maize (Their cotyledons simply shrivel underground as the food is used.)
- Epigeal — Cotyledons come above: Cotyledons are pushed above the soil (Epi- means above.); The hypocotyl elongates and arches upward (The part BELOW the cotyledons grows, so it lifts them out.); Castor, bean and sunflower (Their cotyledons turn green above ground and photosynthesise briefly.); Cotyledons may turn green and make food for a while (Only possible once they are in the light.)
Hint
The trick is which part elongates. hyPOcotyl lifts them UP (epigeal); ePIcotyl leaves them DOWN (hypogeal). The names cross over — that is exactly why it is examined.