Q.The mature seeds of plants such as gram and peas, possess no endosperm, because
Concept understanding — Seed Structure
Seed Structure: The Blueprint of a New Plant
Think of a seed as a survival pod. A plant's entire next generation is packed into a tiny, dormant package that can wait out winter, drought, or any bad season, then burst into life when conditions are right. The seed is not a baby plant — it's a baby plant plus its packed lunch, all wrapped in a protective coat.
Every seed has three essential parts: a seed coat (the protective wrapper), an embryo (the tiny future plant), and a food supply (either stored inside the embryo itself or in a separate tissue called endosperm). The way these parts are arranged differs between the two major groups of flowering plants: dicots and monocots.
The Embryo Axis: The Plant's Spine
At the heart of every seed lies the embryo axis — the miniature stem-root system of the future plant. It has two ends:
- Radicle — the embryonic root, which will grow downward into the soil.
- Plumule — the embryonic shoot, which will grow upward toward the light.
Attached to this axis are the cotyledons (seed leaves). These are the first leaves the plant produces, but they often never see sunlight — their job is to absorb or store food for the germinating seedling.
Dicot Seed Structure
Take a bean seed — a classic dicot. Split it open and you see two large, fleshy halves. Those halves are the cotyledons. They are thick because they are the food supply. The endosperm was absorbed during seed development, and its nutrients were transferred into the cotyledons. So a dicot seed like bean or pea has no endosperm at maturity — the cotyledons themselves serve as storage.
Between the two cotyledons, tucked at one end, lies the embryo axis. The radicle points toward the micropyle (a tiny pore in the seed coat through which water enters during germination). The plumule sits between the cotyledons, protected.
In some dicots (like castor), the endosperm remains at maturity. The cotyledons are thin and papery — they absorb food from the endosperm during germination rather than storing it themselves.
Monocot Seed Structure
Now look at a maize grain (corn). It's not a true seed botanically — it's a fruit called a caryopsis, where the seed coat is fused to the fruit wall — but for practical purposes, we treat it as a seed.
The key difference: monocot seeds have one cotyledon, called the scutellum. It is thin and shield-shaped, pressed against the endosperm. The scutellum does not store food; it acts as a transfer organ, digesting the endosperm and passing nutrients to the growing embryo.
The endosperm in a monocot seed is large and persistent — it makes up most of the seed's bulk. In maize, you can see two distinct regions: the starchy white endosperm (food) and the small, yellowish embryo tucked at one side.
The embryo axis in monocots has the same parts — radicle and plumule — but they are covered by protective sheaths: the coleorhiza covers the radicle, and the coleoptile covers the plumule. These sheaths protect the delicate growing points as they push through soil.
Dicot vs Monocot Seed — The Core Difference
- Dicot: Two cotyledons; endosperm may be present (castor) or absent (bean).
- Monocot: One cotyledon (scutellum); endosperm always present and large.
Putting It All Together
| Feature | Dicot Seed (e.g., Bean) | Monocot Seed (e.g., Maize) |
|---|---|---|
| Cotyledons | Two, fleshy (store food) | One (scutellum, absorbs food) |
| Endosperm | Usually absent (food in cotyledons) | Large and persistent |
| Embryo axis | Radicle + plumule between cotyledons | Radicle + plumule with coleorhiza & coleoptile |
| Seed coat | Thick, separate from fruit wall | Fused to fruit wall (caryopsis) |
The seed is a masterpiece of biological engineering — a dormant plant with its own food supply, waiting for the right signal. When water enters through the micropyle, the radicle emerges first, anchoring the seed. Then the plumule pushes upward, and the cotyledons or endosperm fuel the growth until the first true leaves begin photosynthesis. That moment — from dormant seed to independent seedling — is germination.
This is a core NCERT Class 11 Biology concept from Morphology of Flowering Plants, and it appears in CBSE and NEET Biology question banks under searches like 'Seed Structure: Definition, Diagram & Examples' and 'Seed Structure notes class 11'. Comparing monocot and dicot seed structure, especially the role of endosperm, is a recurring differentiate-type exam question.
In seeds such as gram and pea, an endosperm does form after double fertilisation, but it does not persist in the mature seed. As the embryo develops inside the seed, it draws on the food reserves of the endosperm and consumes them completely, storing the nutrients instead in its own swollen, fleshy cotyledons. By the time the seed is mature, the endosperm has been fully used up, leaving a seed that appears to have no endosperm at all, even though endosperm formation did occur earlier in development.
- Double fertilisation still occurs in these plants
- The endosperm forms but is absorbed by the growing embryo before the seed matures
- Such seeds are called non-endospermic or ex-albuminous
The mature seeds of gram and pea lack endosperm because (D) the endosperm gets used up by the developing embryo during seed development.
Gram and pea seeds appear to have no endosperm simply because the embryo consumes the endosperm's reserves before the seed reaches maturity, not because endosperm never formed.
Gram and pea are flowering plants, and like all angiosperms they undergo double fertilisation, so an endosperm does begin to form after fertilisation. The distinction lies in what happens to that endosperm afterward.
- In seeds such as castor, the endosperm persists right through to maturity as the main food-storing tissue, making the seed endospermic or albuminous.
- In seeds such as bean, gram and pea, the developing embryo actively draws upon and exhausts the endosperm's reserves as it grows, transferring the stored food into its own cotyledons, which become thick and fleshy as a result.
By the time such a seed is fully mature, no endosperm tissue remains to be seen — the food that would have been stored there is now packed inside the cotyledons instead. This is why these are called non-endospermic or ex-albuminous seeds.
So the absence of endosperm in the ripe seed of gram or pea does not reflect a failure of double fertilisation or of endosperm formation; it reflects the endosperm being consumed during development.
Option (D) is correct: the endosperm is formed but gets completely used up by the developing embryo before the seed matures.
Method: Eliminate the Three Wrong Options by Testing Each Against a Known Fact
For exemplar MCQs like this, a fast and reliable method is to test each distractor against something you already know for certain, rather than trying to directly recall the correct explanation.
Known fact: gram and pea are angiosperms, and double fertilisation is a defining, universal feature of angiosperm reproduction, it happens in every flowering plant without exception.
Now test each option against that fact. Option (a), these plants are not angiosperms, is false immediately, since gram and pea are textbook angiosperms, used throughout this very chapter as examples for other topics like tendrils and floral formulas. Option (b), there is no double fertilization in them, is false, because double fertilisation is universal in angiosperms, nothing exempts gram or pea from it. Option (c), endosperm is not formed in them, is false for the same reason, if double fertilisation occurs, an endosperm nucleus is always formed as a first step, even if it does not persist.
Having eliminated (a), (b) and (c) using one shared fact, double fertilisation is universal in angiosperms, only (d) remains, and it must be correct without needing separate proof: the endosperm forms but is subsequently consumed by the growing embryo before the seed matures, with the food reserves relocating into the thickened, fleshy cotyledons instead, which is precisely why such seeds are called non-endospermic.
This process-of-elimination-via-one-fact method is often faster than trying to recall the positive explanation directly, and it also guards against a tempting wrong answer, since (b) and (c) sound superficially plausible unless actively checked against the double-fertilisation rule.
- CBSE 2026Set ANNUAL1 markQ.Write True/False: Stem is developed from the plumule of the embryo of the germinating seed.
›Reveal solutionSolution
This statement is True — the plumule of the germinating seed's embryo develops into the shoot system (stem, leaves, and eventually flowers).
A typical dicot seed embryo consists of an embryonal axis with two cotyledons attached. The portion of the axis above the level of cotyledon attachment is called the epicotyl, which terminates in the plumule (the embryonic shoot tip), and the portion below is the hypocotyl, terminating in the radicle (embryonic root tip). During germination, the radicle grows downward to form the root system, while the plumule grows upward, elongating and differentiating to form the stem and leaves of the young plant (the shoot system).
✓Final answerTrue — the stem develops from the plumule of the embryo of the germinating seed.
- CBSE 2024Set ANN1 markMCQQ.Choose the correct answer Monocot seed consists of one large and shield shaped cotylidon known as ________.(a) Aleurone layer(b) Scutellum(c) Coleoptile(d) Coleorhiza
›Reveal solutionSolution
The single large, shield-shaped cotyledon of a monocot (e.g. maize) seed is called the scutellum.
A monocotyledonous seed such as maize has only one cotyledon, which is broad and shield-shaped and is called the scutellum. It lies adjacent to the endosperm and helps absorb and transfer nutrients from the endosperm to the growing embryo during germination. The embryonal axis in such seeds also bears a coleoptile (covering the plumule) and a coleorhiza (covering the radicle), but neither of these is the cotyledon itself — only the scutellum is.
✓Final answerScutellum.
- CBSE 2024Set ANNUAL1 markMCQQ.In mango, the middle, fleshy, edible part of the fruit is(a)(a) Epicarp(b)(b) Endocarp(c)(c) Mesocarp(d)(d) Exocarp
›Reveal solutionSolution
[!TLDR]
(c) Mesocarp
Why
The pericarp of a mango drupe has three layers: epicarp (outer skin), mesocarp (middle fleshy edible layer), and endocarp (hard stony layer surrounding the seed).
[!ANSWER]
(c) Mesocarp
- CBSE 2023Set ANNUAL1 markMCQQ.Roots are developed from:(a) Radicle(b) Plumule(c) Cotyledons(d) Coleoptile
›Reveal solutionSolution
Roots develop from the radicle, the embryonic root present in the seed.
A typical dicot seed embryo has an embryonal axis with two ends: the radicle (pointing towards the micropyle) and the plumule (the embryonic shoot tip), with two cotyledons attached in between.
- On germination, the radicle elongates first and pushes out of the seed coat, growing downward (positively geotropic) to become the primary/tap root.
- The plumule (option b), by contrast, develops into the shoot system — the stem and leaves.
- Cotyledons (option c) are the seed leaves that store/absorb food for the germinating embryo; they do not give rise to roots.
- The coleoptile (option d) is a protective sheath found only in monocot seeds (e.g., maize) that covers the plumule, not the root.
So among the given options, only the radicle is the structure that develops into the root system.
✓Final answerThe correct option is (a) Radicle — roots develop from the radicle.
- CBSE 2023Set ANNUAL1 markQ.What is the cotyledon of monocot seed called?
›Reveal solutionSolution
The single cotyledon found in monocot seeds (like maize) is specifically termed the scutellum.
Unlike dicot seeds, which have two fleshy cotyledons that themselves store the food reserve, monocot seeds (e.g., grasses like maize, wheat, rice) are typically endospermic — the bulk of stored food lies in a separate endosperm tissue, not in the cotyledon. Here, the single cotyledon is thin and shield-shaped, pressed against the endosperm, and is given the special name scutellum. Its role is to absorb digested food from the endosperm and pass it on to the growing embryo axis during germination. The embryo axis also bears a coleoptile (covering the plumule) and a coleorhiza (covering the radicle) in monocots.
✓Final answerThe cotyledon of a monocot seed is called the scutellum.
- CBSE 2019Set ANNUAL1 markMCQQ.Roots develop from:(a) Radicle(b) Plumule(c) Cotyledon(d) Coleoptile
›Reveal solutionSolution
The primary root of a plant develops from the radicle, the embryonic root present in the seed.
A dicot seed's embryo consists of an embryonal axis with a radicle (embryonic root) at the lower end and a plumule (embryonic shoot) at the upper end, along with one or two cotyledons attached at the node of cotyledons. On germination, the radicle elongates first, breaks through the seed coat, and grows downward (positively geotropic) to become the primary/tap root. The plumule, by contrast, grows upward to form the shoot. Cotyledons are seed-leaves that store or absorb food, and the coleoptile is a protective sheath around the plumule seen specifically in monocots like grasses — neither gives rise to the root.
✓Final answerThe correct option is (a) Radicle — the root develops from the radicle of the embryo.
🎓Unlock everything free for 14 days
- ✓Full step-by-step solutions
- ✓Concept-first explanations
- ✓Methods, shortcuts & mistakes
- ✓PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.