Monocot & Dicot Seeds
Seeds are an integral part of sexual reproduction in plants. Seeds are generally formed as the end product of sexual reproduction in plants and are exclusively found in angiosperms and gymnosperms. Monocot and dicot seeds develop in different ways, but both contain seeds with a seed coat, cotyledons, endosperm and a single embryo. At the most basic level, you can identify each type based on the number of seed leaves. Monocots have one seed leaf whereas dicots have two seed leaves. The cotyledon or seed leaf is the part of the seed that develops into leaves as the plant grows. Cotyledons generally have a swollen appearance as it acts as a food reserve for the developing seedling.
Both monocot and dicot seeds require similar conditions for seed germination. Their seeds must be fully developed, with an embryo, endosperm, appropriate number of cotyledons and a coating. The embryo usually has two ends. The one which forms the shoot tip referred to as plumule and the portion at the lower end which forms the root tip, referred to as radicle. The whole is enclosed within a protective cover, referred to as the seed coat. The seed coat is made up of an outer layer known as testa and an inner layer known as tagmen.
In monocots, the root that emerges first during germination is covered by a coleorhizae or sheath. Its seedlings’ leaves then come forth, sheathed in a layer referred to as a coleoptile. In dicots, a primary root (radicle) emerges from the seed; this root allows water absorption by the new plant. An apical meristem will eventually develop from this radicle and produce the plant’s root system. Then its shoot comes forth from the seed, consisting of the cotyledons, hypocotyl and epicotyl.
In both monocots and dicots, seedlings grow at a slower rate after they emerge above the soil. The seedling first develops roots and then true leaves that can convert sunlight to energy for the plant in a process referred to as photosynthesis.
Characteristics Of Monocot Seeds
- The embryo contains only one cotyledon.
- Plumule is lateral, cotyledons is terminal.
- Plumule and radical are surrounded by coleoptiles and coleorhizae respectively.
- Mostly albuminous.
- Seed germination is hypogeal.
- A large endosperm is present inside the seed, feeding the embryo.
- The plumule goes upward with the plumule sheath.
- Primary root formed from the radical perishes with time and is replaced by a tuft of adventitious roots.
Characteristics Of Dicot Seeds
- The embryo contains two cotyledons.
- Plumule is terminal, cotyledons are lateral.
- Coleoptiles and coleorhizae are absent.
- Mostly albuminous or exalbuminous.
- Seed germination is either hypogeal or Epigeal.
- The seed contains a tiny endosperm.
- The plumule is pushed upwards by the actively growing epicotyl or hypocotyl.
- Radical produces the primary root which persists and bears many lateral roots.
Difference Between Monocot And Dicot Seeds In Tabular Form
|BASIS OF COMPARISON
|The embryo contains only one cotyledon.
|The embryo contains two cotyledons.
|Seed germination is hypogeal.
|Seed germination is either hypogeal or Epigeal.
|Plumule is lateral, cotyledons is terminal.
|Plumule is terminal, cotyledons are lateral.
|Size Of Endosperm
|A large endosperm is present inside the seed, feeding the embryo.
|The seed contains a tiny endosperm.
|Primary root formed from the radical perishes with time and is replaced by a tuft of adventitious roots.
|Radical produces the primary root which persists and bears many lateral roots.
|Coleoptiles and Coleorhizae
|Plumule and radical are surrounded by coleoptiles and coleorhizae respectively.
|Coleoptiles and coleorhizae are absent.
|Growth Of Plumule
|The plumule goes upward with the plumule sheath.
|The plumule is pushed upwards by the actively growing epicotyl or hypocotyl.
|Mostly albuminous or exalbuminous.
Also Read: Difference Between Monocot And Dicot Leaf