Difference Between Monocot and Dicot Embryo

The monocot embryo contains one cotyledon while the dicot embryo contains two cotyledons. This is the key difference between monocot and dicot embryo.

The embryo is developed from the zygote. A zygote is formed due to the fusion of a male gamete with a female gamete in the process of fertilization. The monocot and dicot embryo will undergo further division and differentiation processes.

CONTENTS

1. Overview and Key Difference
2. What is a Monocot Embryo
3. What is a Dicot Embryo
4. Similarities Between Monocot and Dicot Embryo
5. Side by Side Comparison – Monocot vs Dicot Embryo in Tabular Form
6. Summary

What is a Monocot Embryo?

The monocot embryo is an embryo with the presence of only one cotyledon. In the context of the grass family (Family Gramineae), this is referred to as the scutellum. The single cotyledon is typically present at the lateral side of the embryonal axis. At the lower end of this, a radicle and a root cap are present and they are enclosed in a sheath called coleorhiza.

Epicotyl is the portion present above the attachment of the single cotyledon and it consists of a shoot apex and a limited number of leaf primordia. Further, the coleoptile is the structure that encloses the leaf primordia.

What is a Dicot Embryo?

The dicot embryo is the embryo of dicot plants that contains two cotyledons. Hence, these two cotyledons are present at either side of the embryonal axis. Furthermore, these two cotyledons are located laterally.

Here, epicotyl, which is the portion above the cotyledons, terminates with the plumule that is the future shoot. The plumule is present distally in the embryo. The hypocotyl is the region that is present below the level of cotyledons. Finally, the hypocotyl terminates with the development of the embryo into a structure known as the radicle that is the future root. The radicle is the root tip covered by a root cap known as the calyptra.

What are the Similarities Between Monocot and Dicot Embryo?

• Both embryos are derived by the division of the zygote.
• Both Monocot and Dicot Embryo possess cotyledons.
• A plumule is present in both monocot and dicot embryos.

What is the Difference Between Monocot and Dicot Embryo?

Monocot vs Dicot Embryo
The monocot embryo is the embryo with the presence of only one cotyledon.	The dicot embryo is the embryo of dicot plants that contain two cotyledons.
Cotyledon
A single cotyledon is present in monocot embryo.	Two cotyledons are present in dicot embryo.
Position of the Cotyledons
They occur terminally in monocot embryo.	They occur laterally in dicot embryo.
Plumule
Plumule is present laterally in monocot embryo.	Plumule is present distally in dicot embryo.
Coleoptile
Coleoptile (envelope of the plumule) is present in monocot embryo.	No coleoptile is present in dicot embryo.
Coleorrhiza
Radicle protective sheath ( coleorrhiza ) is present in monocot embryo.	Coleorrhiza is absent in dicot embryo.
Scutellum
Scutellum is present in monocot embryo.	Scutellum is absent in dicot embryo.
Suspensor (Size)
Monocot embryonic suspensor is comparatively larger than the dicot suspensor.	Dicot suspensor is larger but smaller than the monocot.

Summary – Monocot vs Dicot Embryo

To summarize the difference between monocot and dicot embryo, the monocot embryo contains only one cotyledon while the dicot embryo contains two cotyledons. Also, the division of the zygote results in an embryo that undergoes further division and differentiation. The differences between monocot and dicot plants are from the differences that are present within the embryo. The plumule is a common structure that is present in both types of embryos.

Reference:

1.“DEVELOPMENT OF DICOT EMBRYO.” BrainKart. Available here  
2.“Embryo in Flowering Plants: Structure, Types and Development.” Your Article Library, 22 Feb. 2014. Available here  

Image Courtesy:

1.’Rice embryo’By Richard Jefferson’s Center for the Application of Molecular Biology to International Agriculture (CAMBIA) – BioForge.net (CC BY-SA 2.5) via Commons Wikimedia
2.’Monocot dicot seed’By Cbenson1919 – Own work, (CC BY-SA 3.0) via Commons Wikimedia