Fruit and Seed — Revision Notes

⚡ 30-Second Revision

Fruit: — Mature/ripened ovary, protects and disperses seeds.
Pericarp: — Fruit wall (epicarp, mesocarp, endocarp).
True Fruit: — Only from ovary (e.g., mango).
False Fruit: — Ovary + other floral parts (e.g., apple, thalamus).
Simple Fruit: — Single ovary of single flower (e.g., pea, mango).
Aggregate Fruit: — Multiple separate ovaries of single flower (e.g., custard apple).
Multiple Fruit: — Entire inflorescence (e.g., pineapple).
Drupe: — Fleshy, stony endocarp, 1-seeded (e.g., mango).
Berry: — Fleshy, multi-seeded, no stony endocarp (e.g., tomato).
Legume: — Dry, dehiscent, splits along two sutures (e.g., pea).
Caryopsis: — Dry, indehiscent, pericarp fused with seed coat (e.g., maize).
Seed: — Fertilized ovule, contains embryo, food, seed coat.
Seed Coat: — Outer protective layers (testa, tegmen), with hilum and micropyle.
Embryo: — Plumule (shoot), Radicle (root), Cotyledon(s).
Epicotyl: — Between plumule and cotyledons.
Hypocotyl: — Between radicle and cotyledons.
Albuminous Seed: — Endosperm present (e.g., castor, maize).
Exalbuminous Seed: — Endosperm absent, food in cotyledons (e.g., pea, bean).
Monocot Seed: — One cotyledon (scutellum), plumule/radicle protected by coleoptile/coleorhiza (e.g., maize).
Dicot Seed: — Two cotyledons, no protective sheaths (e.g., pea).
Seed Dormancy: — Suspended growth, adaptive for survival.

2-Minute Revision

Fruits and seeds are the reproductive marvels of flowering plants. A fruit is the developed ovary, protecting seeds and aiding dispersal. Its wall, the *pericarp*, differentiates into *epicarp*, *mesocarp*, and *endocarp*.

Fruits are classified as simple (from one ovary, like a mango drupe or pea legume), aggregate (from multiple ovaries of one flower, like custard apple), or multiple (from an entire inflorescence, like pineapple).

Remember 'true fruits' (only ovary) vs. 'false fruits' (other floral parts, like apple's thalamus). Seeds are fertilized ovules, housing an *embryo* (with *plumule* for shoot, *radicle* for root, and *cotyledons* for food) and a protective *seed coat* (with *hilum* and *micropyle*).

Seeds are *albuminous* if they retain *endosperm* (e.g., maize) or *exalbuminous* if food is in cotyledons (e.g., pea). Monocot seeds have one cotyledon (*scutellum*) and protective sheaths (*coleoptile*, *coleorhiza*), while dicots have two cotyledons.

Seed dormancy ensures germination at optimal times, and diverse dispersal mechanisms (wind, water, animals) spread the species.

5-Minute Revision

Let's consolidate the crucial aspects of fruits and seeds for NEET. A fruit is the mature ovary, designed for seed protection and dispersal. The fruit wall, or *pericarp*, is key. It has three layers: the outer *epicarp* (skin), the middle *mesocarp* (often fleshy), and the inner *endocarp* (enclosing the seed).

For example, in a mango (a *drupe*), the epicarp is the peel, mesocarp is the edible pulp, and endocarp is the stony pit. This is a *true fruit* because only the ovary forms it. Contrast this with an apple (a *pome*), a *false fruit* where the fleshy edible part is the *thalamus*, not the ovary.

Fruits are classified by their origin: *Simple fruits* from a single ovary (e.g., pea, mango). *Aggregate fruits* from multiple separate ovaries of one flower (e.g., custard apple). *Multiple fruits* from an entire inflorescence (e.g., pineapple). Simple fruits can be fleshy (drupe, berry) or dry (dehiscent like legumes, indehiscent like caryopsis).

Seeds are fertilized ovules, containing an *embryo*, food reserves, and a *seed coat*. The seed coat has a *hilum* (scar) and *micropyle* (pore). The embryo consists of an *embryonal axis* (with *plumule* for shoot and *radicle* for root) and one or two *cotyledons*. The region above cotyledons to plumule is *epicotyl*; below to radicle is *hypocotyl*.

Seeds are *albuminous* if they retain *endosperm* for food (e.g., castor, maize) or *exalbuminous* if endosperm is consumed and food is stored in cotyledons (e.g., pea, bean).

Monocot vs. Dicot Seeds:

Monocot (e.g., Maize): — One cotyledon (*scutellum*), usually albuminous. Plumule covered by *coleoptile*, radicle by *coleorhiza*.
Dicot (e.g., Pea): — Two cotyledons, usually exalbuminous. No protective sheaths for plumule/radicle.

Example: If asked to identify the edible part of a coconut, remember it's a drupe. The fibrous mesocarp is removed, and the edible part is the endosperm (liquid and solid). The hard shell is the endocarp. This highlights the diversity within fruit types.

Finally, *seed dormancy* is crucial for survival, preventing premature germination. Various *seed dispersal* mechanisms (wind, water, animals) ensure species propagation. Understand these adaptations and their examples.

Prelims Revision Notes

Fruit: The Ripened Ovary

Definition: — Mature or ripened ovary, developed after fertilization (or without, in parthenocarpy).
Function: — Protects seeds, aids in dispersal.
Pericarp (Fruit Wall): — Differentiated into:

* Epicarp: Outermost layer (skin). * Mesocarp: Middle layer (fleshy in mango, fibrous in coconut). * Endocarp: Innermost layer (stony in mango, papery in pea).

Classification of Fruits:

* True Fruits: Develop solely from the ovary (e.g., mango, tomato, pea). * False Fruits (Accessory Fruits): Other floral parts (e.g., thalamus in apple, strawberry; pedicel in cashew) contribute to fruit formation.

* Simple Fruits: From a single ovary of a single flower. * Fleshy: Drupe (mango, coconut - stony endocarp, 1-seeded), Berry (tomato, grape - fleshy pericarp, multi-seeded), Pome (apple, pear - false fruit, edible thalamus).

* Dry: * Dehiscent (split open): Legume (pea, bean - splits along two sutures), Follicle (*Delphinium* - splits along one suture), Siliqua (mustard - splits leaving replum), Capsule (cotton).

* Indehiscent (do not split): Achene (sunflower - pericarp free from seed coat), Caryopsis (maize, wheat - pericarp fused with seed coat), Nut (cashew - hard woody pericarp), Samara (elm - winged pericarp).

* Aggregate Fruits: From multiple separate carpels (apocarpous ovary) of a single flower (e.g., custard apple, raspberry). * Multiple (Composite) Fruits: From entire inflorescence (e.g., pineapple, jackfruit, mulberry).

Parthenocarpy: — Fruit formation without fertilization, resulting in seedless fruits (e.g., banana).

Seed: The Fertilized Ovule

Definition: — Fertilized and mature ovule, containing an embryo, food reserves, and protective seed coat.
Seed Coat: — Outer protective covering, derived from integuments. Consists of outer *testa* and inner *tegmen*.

* Hilum: Scar on seed coat, point of attachment to fruit. * Micropyle: Small pore above hilum, for water absorption and gas exchange.

Embryo: — Miniature plant within the seed.

* Embryonal Axis: Consists of: * Plumule: Future shoot. * Radicle: Future root. * Epicotyl: Part of axis between plumule and cotyledon attachment. * Hypocotyl: Part of axis between radicle and cotyledon attachment. * Cotyledons: Seed leaves, one or two, store or absorb food.

Endosperm: — Nutritive tissue, provides food to embryo.
Classification of Seeds:

* Albuminous (Endospermic): Endosperm persists at maturity (e.g., castor, maize, wheat). * Exalbuminous (Non-endospermic): Endosperm consumed during development, food stored in cotyledons (e.g., pea, bean, gram).

Monocotyledonous Seed (Monocot): — One cotyledon (*scutellum*), usually albuminous (e.g., maize, wheat). Plumule covered by *coleoptile*, radicle by *coleorhiza*.
Dicotyledonous Seed (Dicot): — Two cotyledons, usually exalbuminous (e.g., pea, gram). No protective sheaths for plumule/radicle.
Seed Dormancy: — State of suspended growth, adaptive for survival in unfavorable conditions.
Seed Dispersal: — Mechanisms (wind, water, animals) to spread seeds away from parent plant.

Vyyuha Quick Recall

For Fruit Types: Some Apples Make Delicious Berries.

Simple: Develop from a single ovary.
Aggregate: From multiple separate ovaries of a single flower.
Multiple: From an entire inflorescence.
Drupe: Fleshy with stony endocarp (e.g., Mango).
Berry: Fleshy, multi-seeded (e.g., Tomato).