Dicotyledonous and Monocotyledonous Seeds: Structure, Differences, Examples

Edited By Irshad Anwar | Updated on Jul 02, 2025 07:13 PM IST

Monocot and dicot seeds are the two kinds of angiosperm seeds, differentiated by the number of cotyledons they have. Monocot seeds have a single cotyledon and typically store food in the endosperm. The seed is protected by a seed coat, and the parts of a seed include the plumule, radicle, and a structure called a scutellum that helps absorb nutrients.

This Story also Contains

What is a Seed?
Structure and Anatomy of Seeds
Dicotyledonous Seeds
Monocotyledonous Seeds
Comparative Analysis between Dicot and Monocot Seeds
MCQs on Dicot and Monocot Seeds

Dicotyledonous and Monocotyledonous Seeds: Structure, Differences, Examples

Dicot seeds have two cotyledons and store food for the growing embryo. The endosperm is fully absorbed during the germination of the seed. There are differences between the monocot and dicot seeds in terms of structural and growth patterns, as well as root and shoot development. Monocot and Dicot seeds are important topics in the field of biology.

What is a Seed?

A seed is a fertilised ovule that contains an embryo, endosperm, and a seed coat for its protection. Seeds are the simplest structures of reproduction in plants that provide them with a means to reproduce, disperse, and colonise new areas. They represent the main way by which plant species can survive through generations.

Seeds fall into two major groups: dicotyledonous (dicot) and monocotyledonous (monocot). Dicot seeds are those that have two cotyledons, e.g., beans and sunflowers. Monocots are those with one cotyledon, e.g., grasses and lilies. The leaves also have different vein patterns: the veins form reticulate venation in dicots and parallel venation in monocots. The differences reflect separate lines of evolution and affect the overall development and structure of the plant.

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Structure and Anatomy of Seeds

Seeds are complex organs that contain the embryo and serve to provide nourishment for its development. A normal seed contains: the cotyledons, the embryo, which will become the new plant; the seed coat, which protects the seed from environmental damage; and the endosperm, inside the seed, which provides nutrients to the growing embryo. These are distinguished by the existence of two cotyledons and a more complex embryonic structure in dicot seeds. And the monocot seeds bear a single cotyledon with less complex embryonic development.

Dicotyledonous Seeds

Dicot seeds, such as those of beans and peas, have two cotyledons that store food for the developing embryo. These seeds typically lack endosperm at maturity, as the nutrients are stored in the cotyledons themselves. The details are given below:

Characteristics of Dicotyledonous Seeds

Dicotyledonous seeds, or dicots, have two cotyledons that are the nutrient storage organs of the seed for the developing embryo. Some examples include beans, peas, and sunflowers—each of these examples has seeds which come in many different shapes and sizes.

Germination Process

The most common kind of germination that occurs in a dicot seed is when the seed imbibes water, swells, and the coat cracks open. Firstly, the cotyledons grow out, followed by the development of the true leaves. These three stages of germination—seed imbibition, radicle emergence, and cotyledon expansion—are all very important in establishing the seedling.

Monocotyledonous Seeds

Monocot seeds, like maize or wheat, contain only one cotyledon and usually retain a large endosperm for nutrient storage. The cotyledon, known as the scutellum, absorbs nutrients from the endosperm during germination. The details are explained below-

Characteristics of Monocotyledonous Seeds

Monocotyledonous seeds, or monocots, are characterised by having a single cotyledon. This single cotyledon plays a role in nutrient absorption and seedling establishment. Examples: Corn, wheat, rice.

Germination Process

The germination process of a Monocot seed, for example, Corn, involves the absorption of water and swelling. They first develop and grow downward was the radicle—or primary root—followed by growth upward of the shoot, composed of the cotyledon with its first true leaves. Stages of germination include imbibition, radicle elongation, and coleoptile growth, all processes necessary for the seedling to break free from the seed.

Comparative Analysis between Dicot and Monocot Seeds

Structurally, dicots generally show a more straightforward embryo, while monocots feature specialised structures like the scutellum and coleoptile for seedling protection and growth. The differences between the seeds in various aspects are given below-

Aspect	Dicotyledonous Seeds (Dicots)	Monocotyledonous Seeds (Monocots)
Structural Differences	Cotyledons: 2 cotyledons, usually broad and fleshy. Seed Coat: Often thicker and more protective. Embryo: Typically larger and more complex. Endosperm: This may be absorbed during development.	Cotyledons: 1 cotyledon, typically narrow and more elongated. Seed Coat: Usually thinner and less protective. Embryo: Smaller and simpler. Endosperm: Often remains as a major nutrient source.
Growth Patterns	Initial Growth: Cotyledons usually emerge above the soil. Leaf Structure and leaf venation: Typically have broad leaves with a network of veins (reticulate venation). Stem Growth: Vascular bundles are arranged in a ring.	Initial Growth: Cotyledon remains below the soil. Leaf Structure and Venation: Narrow leaves with parallel venation. Stem Growth: Vascular bundles are scattered throughout the stem.
Root and Shoot Development	Root Development: Often develops a main taproot system with lateral roots. Shoot Development: Shoots and leaves expand rapidly after cotyledons.	Root Development: Typically forms a fibrous root system with no main root. Shoot Development: The shoot is enclosed by a coleoptile, and leaves develop from the tip.

MCQs on Dicot and Monocot Seeds

Q1. Monocotyledonous seeds are endospermic, but ____ are non-endospermic

Option 1: Wheat

Option 2: Rice

Option 3: Maize

Option 4: Orchids

Correct answer: 4) Orchids

Explanation:

Monocotyledonous seeds - Monocotyledonous seeds are endospermic, but some are non-endospermic (orchid). Monocotyledonous seeds are endospermic, storing food in the endosperm for the developing embryo, but some, like orchids, are non-endospermic. They have a single cotyledon, called the scutellum, which aids in nutrient absorption. The outer covering consists of the seed coat, which protects the embryo. Examples include seeds of grasses like wheat, maize, and rice.

Hence, the correct answer is option 4) Orchids

Q2. Seed is

Option 1: Fertilised embryo

Option 2: Fertilised ovary

Option 3: Fertilised fruit

Option 4: Fertilised Ovule

Correct answer: 4) Fertilised Ovule

Explanation:

The fertilised ovule is the seed. Ovules convert into seeds. The fertilised ovule develops into a seed following the process of fertilisation in plants. The zygote within the ovule grows into an embryo, while the ovule's integuments form the seed coat. The seed contains stored nutrients in the form of endosperm or cotyledons, supporting the growth of the embryo during germination. The ovary surrounding the ovule matures into a fruit, protecting the seed and aiding in its dispersal. Seeds are crucial for reproduction and propagation in plants, ensuring the survival of the species.

Hence, the correct answer is option 4) Fertilised Ovule

Q3. The most appropriate definition of a seed in terms of its homologous organs found in spore-producing land plant is :

Option 1: A seed is an integumented sporangium with a single functional spore

Option 2: A seed is an integumented indehiscent megasporangium

Option 3: A seed is an integumented bud containing an egg

Option 4: None of the above

Correct answer: 2) A seed is an integumented indehiscent megasporangium

Explanation:

A seed is defined as an integumented indehiscent megasporangium. This means it is a reproductive structure surrounded by one or more protective layers called integuments, which are derived from the sporophytic tissue of the parent plant. The term is indehiscent indicates that the seed does not naturally split open at maturity to release its contents, instead remaining closed until favourable conditions for germination occur. The megasporangium within the seed houses the megaspore, which develops into the female gametophyte. This structure ensures the protection, nourishment, and dispersal of the embryo, making it a key adaptation for survival and reproduction in seed plants.

Hence, the correct answer is option 2) A seed is an integumented indehiscent megasporangium

Other Useful Resources:

Pollen-Pistil Interaction & Outbreeding Devices	Artificial Hybridization in Plants - Emasculation and Bagging
Self incompatibility	Post Fertilization - Events and Changes in Flowering Plants
Differences between Megasporogenesis and Microsporogenesis	Dicotyledonous and Monocotyledonous Seeds

Frequently Asked Questions (FAQs)

1. What are the main differences between dicotyledonous and monocotyledonous seeds?

Dicotyledonous seeds have two cotyledons, the broad, fleshy parts of plants which become seed leaves at germination; monocotyledonous seeds contain only one, narrow cotyledon. Another distinction is the thickness of seed coats and size of embryos: thicker seed coat and larger embryo in dicots and thinner seed coat and smaller embryo in monocots. Further to the issue of nutrient supply, the endosperm is usually absorbed during development in dicots but in monocots persists as a principal source of nutrients.

2. What are the main differences between dicotyledonous and monocotyledonous seeds?

Dicotyledonous seeds have two cotyledons, while monocotyledonous seeds have one. Dicot seeds typically have a bilateral symmetry, whereas monocot seeds are usually radially symmetrical. The embryo position and endosperm amount also differ between the two types.

3. How do dicot and monocot seeds germinate differently?

The cotyledons of most of the dicot seeds grow upwards outside the soil and then leaves are formed to produce early nourishment. In the case of monocot seeds, the cotyledon remains below the ground and shoots through coleoptile.

4. Can you provide examples of dicot and monocot seeds?

Dicot seeds would be beans, peas, and sunflowers. Corn, wheat, and rice are monocot seeds. With these examples, we use them to show or display a structural difference that exhibits functionality in the two seed types.

5. Why is it important to understand the differences between dicots and monocots in agriculture?

This is important in agriculture because that dictates the methods to be used in planting, managing crops, and applying other applicable farming practices. For instance, knowledge of the structure of seeds and germination patterns may affect soil preparation, irrigation, use of fertilizers, and pesticides applied to such crops, hence affecting crop yield and quality.

6. What role do dicot and monocot seeds play in plant evolution and diversity?

Two major evolutionary lines, the dicot and monocot seeds, are significant contributions to plant diversity. This differentiation enables plants to adapt to forms and functions. Their study enabled researchers to learn about plant evolution, ecological interactions and the production of new varieties of plants.

7. Why are cotyledons important for seed germination?

Cotyledons are crucial for seed germination because they store food reserves that nourish the developing embryo until it can produce its own food through photosynthesis. In some plants, cotyledons also become the first leaves, allowing the seedling to begin photosynthesis quickly.

8. How does the arrangement of vascular bundles differ in dicot and monocot stems?

In dicot stems, vascular bundles are arranged in a ring, while in monocot stems, they are scattered throughout the ground tissue. This difference in arrangement affects the plant's growth patterns and structural support.

9. What is the endosperm, and how does its presence differ between dicots and monocots?

The endosperm is a nutritive tissue that provides food for the developing embryo. In most monocots, the endosperm persists in mature seeds and is the primary source of nutrition during germination. In many dicots, the endosperm is absorbed by the cotyledons during seed development, and the cotyledons become the primary source of nutrition.

10. How do the root systems of dicots and monocots typically differ?

Dicots usually have a taproot system with a main root and smaller lateral roots, while monocots typically have a fibrous root system with many roots of similar size. This difference affects how the plants anchor themselves and absorb water and nutrients from the soil.

11. How do dicot and monocot embryos differ in their organization?

Dicot embryos typically have two clearly defined cotyledons, a radicle (embryonic root), and a plumule (embryonic shoot). Monocot embryos have one cotyledon (scutellum), a radicle, and a plumule, but these parts are often less distinctly organized.

12. How does seed size relate to endosperm content and cotyledon size?

Generally, seeds with larger endosperms tend to have smaller cotyledons, as in many monocots. Seeds with little or no endosperm often have larger cotyledons that store food, as seen in many dicots. Seed size can vary greatly and doesn't always correlate directly with these factors.

13. What is vivipary, and how does it differ from typical seed development?

Vivipary is a phenomenon where seeds germinate while still attached to the parent plant. This is different from typical seed development, where seeds are dispersed before germination. Vivipary is an adaptation seen in some plants, particularly those in aquatic or very moist environments.

14. How do polyembryonic seeds differ from typical seeds?

Polyembryonic seeds contain multiple embryos, unlike typical seeds with a single embryo. This can result in multiple seedlings from a single seed. Polyembryony occurs naturally in some plants and can also be induced artificially, having implications for plant propagation and genetics.

15. How do seed storage proteins differ between dicots and monocots?

Dicots often store proteins in protein bodies within the cotyledons, while monocots typically store proteins in the endosperm. The types of proteins can also differ, with legumes (dicots) rich in proteins like legumin, while cereals (monocots) contain proteins like gluten.

16. What is the function of the scutellum in monocot seeds?

The scutellum is a modified cotyledon in monocot seeds that absorbs nutrients from the endosperm and transfers them to the growing embryo. It plays a crucial role in the germination and early growth of monocot seedlings.

17. How does the hilum function in seeds?

The hilum is the scar on the seed coat where the seed was attached to the ovary wall. It serves as a weak point in the seed coat, often allowing water to enter during imbibition and facilitating the emergence of the radicle during germination.

18. What is the aleurone layer, and what role does it play in seed germination?

The aleurone layer is the outermost layer of the endosperm in grass seeds (monocots). It plays a crucial role in germination by producing enzymes that break down stored nutrients in the endosperm, making them available to the growing embryo.

19. How do the embryo positions differ between dicot and monocot seeds?

In dicot seeds, the embryo is typically curved or folded, with the cotyledons and radicle clearly visible. In monocot seeds, the embryo is usually small and straight, located to one side of the endosperm.

20. What is epigeal germination, and how does it differ from hypogeal germination?

In epigeal germination, the cotyledons emerge above the soil surface and often become photosynthetic. In hypogeal germination, the cotyledons remain below ground. Epigeal is common in many dicots, while hypogeal is more common in monocots and some dicots.

21. What is the function of the micropyle in seeds?

The micropyle is a small pore in the seed coat that allows water to enter the seed during imbibition, which is the first step in germination. It also serves as the entry point for the pollen tube during fertilization in the ovule.

22. What is the significance of the plumule in seed structure?

The plumule is the embryonic shoot that will develop into the stem and leaves of the plant. It's crucial for the seedling's above-ground growth and development, ensuring the plant can begin photosynthesis once it emerges from the soil.

23. How does seed coat structure contribute to seed dormancy?

The seed coat can contribute to dormancy by being impermeable to water or oxygen, or by containing chemical inhibitors. This structure helps prevent premature germination and allows seeds to survive unfavorable conditions until the environment is suitable for growth.

24. What is the role of the pericarp in seed structure and function?

The pericarp is the outermost layer of the fruit that encloses the seed. In some plants, it fuses with the seed coat, providing additional protection. The pericarp can play roles in seed dispersal, protection from predators, and regulation of germination timing.

25. How does seed coat impermeability contribute to seed longevity?

An impermeable seed coat can prevent water and oxygen from entering the seed, maintaining seed dormancy and preventing premature germination. This helps seeds survive in soil seed banks for extended periods, sometimes for years or even decades, until conditions are favorable for germination.

26. What is seed stratification, and why is it important for some seeds?

Seed stratification is the process of exposing seeds to cold and moist conditions to break dormancy. It's important for seeds of many temperate plants that require a period of winter-like conditions before they can germinate, ensuring they sprout at the appropriate time of year.

27. What is the difference between orthodox and recalcitrant seeds?

Orthodox seeds can withstand drying and freezing, allowing for long-term storage. Recalcitrant seeds cannot survive drying and must maintain high moisture content, making them difficult to store. This difference affects seed longevity and storage practices in agriculture and conservation.

28. What is the role of phytohormones in seed dormancy and germination?

Phytohormones like abscisic acid (ABA) and gibberellins play crucial roles in regulating seed dormancy and germination. ABA promotes dormancy, while gibberellins promote germination. The balance between these hormones, influenced by environmental conditions, determines when a seed will germinate.

29. How does seed coat thickness relate to seed dormancy and germination timing?

Thicker seed coats often correlate with longer dormancy periods and delayed germination. They can provide greater protection against environmental stresses and predators but may require more specific conditions (like scarification) to break dormancy and allow germination.

30. What is the function of the radicle in seed structure?

The radicle is the embryonic root and the first part of the seedling to emerge during germination. It grows downward into the soil, anchoring the seedling and beginning to absorb water and nutrients, which is crucial for the plant's early survival and establishment.

31. How do dicot and monocot leaves differ in their venation patterns?

Dicot leaves typically have netted or reticulate venation, with veins branching out in various directions. Monocot leaves usually have parallel venation, with veins running parallel to each other along the length of the leaf. These patterns affect leaf structure and function.

32. How do dicot and monocot flowers typically differ in their floral parts?

Dicot flowers usually have floral parts in multiples of four or five (e.g., 5 petals, 5 sepals), while monocot flowers typically have parts in multiples of three (e.g., 3 petals, 3 sepals). This difference reflects the overall structural patterns of these plant groups.

33. What is the coleoptile, and what is its function in monocot seeds?

The coleoptile is a protective sheath that covers the emerging shoot in monocot seeds. It helps the shoot push through the soil without damage and responds to light, guiding the seedling's growth towards the surface.

34. How do seed dispersal mechanisms differ between dicots and monocots?

While both dicots and monocots exhibit various dispersal mechanisms, some trends exist. Many dicots have fleshy fruits for animal dispersal or winged seeds for wind dispersal. Monocots often have lightweight seeds for wind dispersal or hooks for animal dispersal. However, there's significant variation within each group.

35. What is the difference between endospermic and non-endospermic seeds?

Endospermic seeds retain their endosperm in mature seeds, which provides nutrition during germination. Non-endospermic seeds have little or no endosperm at maturity, with food reserves stored in the cotyledons instead. Many monocots are endospermic, while many dicots are non-endospermic.

36. How does seed size affect germination rate and seedling vigor?

Generally, larger seeds tend to have higher germination rates and produce more vigorous seedlings. This is because they contain more stored nutrients to support early growth. However, smaller seeds often have advantages in dispersal and can be produced in greater numbers.

37. What is seed priming, and how does it affect germination?

Seed priming is a technique where seeds are partially hydrated to initiate metabolic processes before planting. This can lead to faster, more uniform germination and improved seedling vigor. Priming can be particularly useful for old or slow-germinating seeds.

38. How do dicot and monocot seeds differ in their protein storage patterns?

Dicot seeds often store proteins in specialized protein bodies within the cotyledons. Monocot seeds typically store proteins in the endosperm, often in protein bodies embedded in a starch matrix. These differences affect how nutrients are mobilized during germination.

39. What is the role of the suspensor in seed development?

The suspensor is a structure that connects the developing embryo to the parent plant. It plays a crucial role in early seed development by supporting the embryo, transferring nutrients, and producing growth regulators. The suspensor usually degenerates as the seed matures.

40. How do environmental factors influence seed dormancy and germination?

Environmental factors like temperature, light, moisture, and oxygen levels can influence seed dormancy and germination. Some seeds require specific conditions (like cold stratification or light exposure) to break dormancy, ensuring germination occurs under favorable conditions for seedling survival.

41. What is seed scarification, and why is it necessary for some seeds?

Seed scarification is the process of breaking, scratching, or softening the seed coat to allow water absorption and gas exchange. It's necessary for seeds with hard, impermeable seed coats to overcome physical dormancy and initiate germination.

42. How do dicot and monocot seeds differ in their carbohydrate storage patterns?

Dicot seeds often store carbohydrates as starch granules in the cotyledons. Monocot seeds typically store carbohydrates as starch in the endosperm. This difference affects how energy is mobilized during germination and early seedling growth.

43. What is the function of the coleorhiza in monocot seeds?

The coleorhiza is a protective sheath that covers the radicle (embryonic root) in monocot seeds. It helps protect the radicle as it emerges through the seed coat and soil during germination, similar to how the coleoptile protects the emerging shoot.

44. How does seed coat permeability affect imbibition and germination?

Seed coat permeability regulates water uptake during imbibition, the first step of germination. Highly permeable seed coats allow rapid water uptake, which can lead to faster germination but may also cause imbibitional damage. Less permeable coats slow water uptake, which can protect against damage but may delay germination.

45. What is seed polymorphism, and how does it affect plant survival strategies?

Seed polymorphism is the production of different types of seeds by a single plant. This can include differences in size, shape, or dormancy characteristics. It's a strategy that increases the chances of successful reproduction by allowing seeds to germinate under different conditions or at different times.

46. How do dicot and monocot seeds differ in their lipid storage patterns?

Dicot seeds often store lipids in oil bodies (oleosomes) within the cotyledons. Monocot seeds typically have less lipid storage, with what lipids they do have often found in the aleurone layer or embryo. These differences reflect the overall energy storage strategies of the two groups.

47. What is the role of hydrolytic enzymes during seed germination?

Hydrolytic enzymes play a crucial role in breaking down stored nutrients (like starch, proteins, and lipids) into simpler forms that can be used by the growing embryo. These enzymes are often produced in the aleurone layer or cotyledons and are activated during germination.

48. How does seed shape affect dispersal mechanisms?

Seed shape can significantly influence dispersal. For example, flat or winged seeds are adapted for wind dispersal, round seeds may be suited for rolling, and seeds with hooks or barbs are adapted for animal dispersal. Seed shape is often closely tied to the plant's dispersal strategy.

49. What is seed dormancy, and how does it differ between dicots and monocots?

Seed dormancy is a state in which seeds are prevented from germinating even under favorable conditions. While both dicots and monocots can exhibit dormancy, the mechanisms can differ. For example, many temperate dicots require cold stratification to break dormancy, while some grass seeds (monocots) have hormone-mediated dormancy.

50. How does the presence or absence of endosperm affect seed germination strategies?

Seeds with abundant endosperm (like many monocots) often have a strategy where the endosperm provides nutrition throughout early growth. Seeds with little or no endosperm (common in dicots) rely on stored nutrients in the cotyledons, which often become the first photosynthetic organs. This affects the timing and energy dynamics of early seedling growth.

51. What is the significance of the embryonic axis in seed structure?

The embryonic axis is the part of the embryo that will develop into the new plant. It includes the radicle (embryonic root) and plumule (embryonic shoot). The orientation and development of the embryonic axis are crucial for proper seedling emergence and establishment.

52. How do dicot and monocot seeds differ in their mineral storage and mobilization?

Dicot seeds often store minerals like phosphorus in specialized structures called globoids within protein bodies. Monocot seeds typically store minerals in the aleurone layer or scattered throughout the endosperm. These differences affect how minerals are mobilized and used during germination.

53. What is seed vigor, and how does it relate to seed structure?

Seed vigor refers to the seed's ability to germinate and establish a normal seedling under a wide range of environmental conditions. It's influenced by factors like seed size, nutrient content, and embryo development. Generally, seeds with well-developed embryos and ample nutrient reserves tend to have higher vigor.

54. How do the germination requirements of epigeal and hypogeal seeds differ?

Epigeal germination (where cotyledons emerge above ground) requires more energy for the hypocotyl to elongate and push the cotyledons up. Hypogeal germination (where cotyledons remain below ground) requires less initial energy but may result in slower photosynthetic capability. These