Question

Write the difference between epigeal and hypogeal germination.

Answer 1

Hint : Cotyledons remain below the soil surface in hypogeal germination while they emerge on to the surface in the epigeal germination.

Complete answer : Let us begin with defining the germination. It is the process of development or emergence of the baby plant from seed. The embryo present in the seed develops to give rise to the baby plant or seedling.

The germination can be of two types, depending on the positioning of the cotyledons or seed leaves:

If the cotyledons remain below the soil, it is called hypogeal germination
If the cotyledons emerge on the surface of the soil, is called epigeal germination

Now, let us figure out the differences between these two types of germination:

Epigeal Germination	Hypogeal Germination
The cotyledons are brought on the surface of the soil along with the shoot	Cotyledons remain below the soil surface
The hypocotyl has a curved terminal part to protect the plumule as it comes out of the soil	The epicotyl has a curved terminal part to protect the plumule from friction in soil particles
The hypocotyl grows excessively to bring the cotyledons out of the soil	The hypocotyl does not show much elongation
The plumule comes out of the seed by the elongation of the hypocotyl	The plumule comes out of the seed by the elongation of the epicotyl
The energy for the growth comes from the cotyledons	The energy primarily comes from the endosperm
Epicotyl is short	Epicotyl is long
The cotyledons turn green and perform photosynthesis	The cotyledons have no role in photosynthesis
It is generally shown by the dicot seeds	It is generally shown by the monocot seeds
It occurs in beans, onion, papaya, castor, etc	It occurs in coconut, gram, maize, etc.

Note : Both the endosperm and cotyledons are the nutritive tissues. The cotyledons perform a prominent role in nutrition in seedling with seeds showing epigeal germination.