Plants Germination
Primary 4 · Science and Elementary Technology
Plants Germination
Lesson 3 of 5
12 min
Let's begin
Ishimwe plants beans and maize in the school garden on the same day. A week later, the beans have pushed two fat, round seed leaves up out of the soil. The maize has sent up only a thin green spike, and its grain has stayed hidden in the ground.
Why do they look so different? They use two different types of germination.
Epi means "on" or "above". The part of the young stem below the cotyledons grows long and pushes the cotyledons up out of the soil. They turn green for a short time.
Examples: common beans, soya beans, sunflower, pumpkin.
Hypo means "under". The part of the stem above the cotyledons grows, so only the shoot comes up. The cotyledons, or the food store, stay under the soil and feed the seedling from there.
Examples: maize, sorghum, rice, peas, avocado.
| Epigeal | Hypogeal | |
|---|---|---|
| Where the cotyledons go | above the ground | stay under the ground |
| Examples | bean, soya bean, sunflower, pumpkin | maize, sorghum, rice, pea, avocado |
Tip
Epigeal: Everything Pops up. Hypogeal: it Hides in the ground
Try each one first, then tap Show answer to check.
Which type of germination does a common bean have?
Answer: Epigeal: its cotyledons come above the ground.
Which type of germination does maize have?
Answer: Hypogeal: its grain stays under the ground.
What does "hypo" mean?
Answer: Under or below.
Why should bean seeds not be planted too deep?
Answer: The seedling has to push its cotyledons up through the soil, and too much soil can stop it.
Where are the cotyledons of a pea seedling?
Answer: Under the ground, because peas have hypogeal germination.
What you learned today
Sources and credits
The exercises (Try it yourself and the practice questions) are written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
Quick check
Which seed has hypogeal germination?
