NCERT

Every NCERT book that matters for UPSC — open a book, then a chapter. Learn each chapter's concepts, then how UPSC tests them — with diagrams, flowcharts and the past questions to attempt.

Class 6	Exploring Society: India and Beyond	Social Science	14 of 14
Class 7	Our Environment	Geography	7 of 7
Class 7	Our Pasts – II	History	8 of 8
Class 7	Social and Political Life – II	Polity	8 of 8
Class 8	Resource and Development	Geography	5 of 5
Class 8	Our Pasts – III	History	8 of 8
Class 8	Social and Political Life – III	Polity	8 of 8
Class 9	Exploration	Science	4 of 13
Class 9	Understanding Society: India and Beyond – I	Social Science	9 of 9
Class 9	Understanding Society: India and Beyond – II	Social Science	6 of 6
Class 10	Understanding Economic Development	Economics	5 of 5
Class 10	Contemporary India – II	Geography	7 of 7
Class 10	India and the Contemporary World – II	History	5 of 5
Class 10	Democratic Politics – II	Polity	5 of 5
Class 10	Science	Science	13 of 13
Class 11	An Introduction to Indian Art – Part I	Art & Culture	8 of 8
Class 11	Biology	Biology	5 of 19
Class 11	Indian Economic Development	Economics	8 of 8
Class 11	Fundamentals of Physical Geography	Geography	14 of 14
Class 11	India: Physical Environment	Geography	6 of 6
Class 11	Themes in World History	History	7 of 7
Class 11	Indian Constitution at Work	Polity	10 of 10
Class 11	Political Theory	Polity	8 of 8
Class 11	Psychology	Psychology	8 of 8
Class 11	Introducing Sociology	Sociology	5 of 5
Class 11	Understanding Society	Sociology	5 of 5
Class 12	Biology	Biology	13 of 13
Class 12	Introductory Macroeconomics	Economics	6 of 6
Class 12	Introductory Microeconomics	Economics	5 of 5
Class 12	Fundamentals of Human Geography	Geography	8 of 8
Class 12	India: People and Economy	Geography	9 of 9
Class 12	Themes in Indian History – I	History	4 of 4
Class 12	Themes in Indian History – II	History	4 of 4
Class 12	Themes in Indian History – III	History	4 of 4
Class 12	Contemporary World Politics	Polity	7 of 7
Class 12	Politics in India since Independence	Polity	8 of 8
Class 12	Psychology	Psychology	7 of 7
Class 12	Indian Society	Sociology	7 of 7
Class 12	Social Change and Development in India	Sociology	8 of 8

0% read

← Biology — all chapters

Class 11BiologyBiologyChapter 5

Morphology of Flowering Plants

≈ 40 min read · 4 Prelims and 0 Mains questions from this chapter

Attempt questions

Start here: why this chapter matters

In simple wordsThis chapter is a vocabulary lesson for plants. A doctor needs words like ‘sternum’ and ‘femur’ to describe a body precisely; a botanist needs ‘petiole’, ‘phyllotaxy’, ‘hypogynous’ and ‘axile’. Learn the words once and you can read any plant — and answer the many exam questions that hide behind them, such as ‘is a potato a root or a stem?’

This is Chapter 5 of NCERT's Class 11 Biology (pages 57–70 of the 2026-27 reprint), the first chapter of Unit II, Structural Organisation in Plants and Animals; the PDF also carries the unit opener and a profile of the plant anatomist Katherine Esau (pages 55–56). It has nine sections — 5.1 The Root to 5.7 The Seed, 5.8 Semi-technical Description of a Typical Flowering Plant and 5.9 Solanaceae — with Figures 5.1–5.17, a summary and 10 exercises. Earlier editions also taught modifications of root, stem and leaf and the families Fabaceae and Liliaceae; the reprint has dropped them. No exercise asks about those families, so they are not restored, but the reprint's own Summary still mentions modified roots, so section 9 covers the modifications as Beyond the reprint. Angiosperms as a group, and dicots versus monocots, were introduced in Chapter 3, Plant Kingdom (kebo103).

Neighbouring chapters: Anatomy of Flowering Plants (Chapter 6) cuts open the root, stem and leaf described here; Sexual Reproduction in Flowering Plants (lebo101) follows the stamen, carpel, ovule and seed through pollination, double fertilisation and endosperm; Plant Kingdom (kebo103) placed the angiosperms among the plant groups; Biotechnology and its Applications (lebo110) covers Bt crops, including Bt brinjal of the potato family.
Prelims — science and agriculture: UPSC has asked which vegetable is a modified stem (potato, 1996), what matches fruit, seed, wood and starch (1998), which flower part gives saffron (the stigma, 2009), which root parts do what (1986) and, from the modifications earlier editions taught, the part of the plant that gives turmeric (1983) and the part that forms the pitcher of a pitcher plant (2007).
GS3 — Agriculture, Science & Technology: crop plants identified by their parts (tubers, rhizomes, grains, drupes); the potato family as a food, spice and drug family; seeds, endosperm and grain structure for food processing; GM vegetables (Bt brinjal) as a regulatory debate.

Word	What it means here
Morphology	the study of a plant's external form and structure
Radicle / plumule	the embryo's root end / shoot end: they give the root and the stem
Node / internode	the point on a stem where leaves arise / the stretch between two nodes
Axil	the angle between a leaf (petiole) and the stem, where a bud sits
Thalamus (receptacle)	the swollen end of the flower stalk on which the floral whorls sit
Whorl	a ring of similar parts: calyx (sepals), corolla (petals), androecium (stamens), gynoecium (carpels)
Carpel	the female unit: stigma, style and ovary; several make the gynoecium
Ovule / placenta	the body that becomes a seed / the cushion inside the ovary on which ovules sit
Pericarp	the fruit wall, from the ovary wall
Endosperm	a food-storing tissue formed by double fertilisation (lebo101)

Reading NCERT's Unit II opener and chapter opening (pages 55, 57)The unit opener argues that biology was long a natural history of description, and that detailed description later helped reductionist biology frame questions in physiology and evolution; it lists Chapters 5–7. The chapter opening says that despite their diversity all angiosperms have roots, stems, leaves, flowers and fruits, and that classifying them needs standard technical terms — including the variations that adapt plants to habitat, protection, climbing and storage. The point: this chapter is the shared vocabulary for everything that follows.

Reading NCERT's Katherine Esau box (page 56)A photograph of Katherine Esau (1898–1997) beside a short profile: born in Ukraine, trained in agriculture in Russia and Germany, doctorate in the United States in 1931; she showed that the curly top virus spreads through the phloem; her Plant Anatomy (1954) and Anatomy of Seed Plants (1960) revived the discipline; elected to the US National Academy of Sciences in 1957 (the sixth woman so honoured) and given the National Medal of Science in 1989. The point: describing plant structure carefully is real science with practical payoffs, such as tracing how a plant virus moves.

At a glance — the six ideas to carry away

Roots: tap (from the radicle; mustard, most dicots), fibrous (from the stem base; wheat, most monocots), adventitious (from any part other than the radicle; grass, Monstera, banyan). Root tip from the apex up: root cap → meristematic region → elongation → maturation (root hairs absorb water and minerals).
Stem: from the plumule; nodes, internodes, terminal and axillary buds. Leaf: leaf base (+ stipules; sheath in monocots; pulvinus in some legumes), petiole, lamina with midrib. Venation: reticulate (dicots), parallel (monocots). Compound: pinnate (neem, rachis), palmate (silk cotton). Phyllotaxy: alternate (china rose), opposite (Calotropis, guava), whorled (Alstonia).
Inflorescence: racemose — axis keeps growing, flowers acropetal; cymose — axis ends in a flower, basipetal. Flower = modified shoot; thalamus bears calyx, corolla (accessory) and androecium, gynoecium (reproductive); perianth in lily. Symmetry: actinomorphic (mustard, datura, chilli), zygomorphic (pea, gulmohur, bean, Cassia), asymmetric (canna).
Ovary position: hypogynous — superior (mustard, china rose, brinjal); perigynous — half inferior (plum, rose, peach); epigynous — inferior (guava, cucumber, sunflower ray florets). Aestivation: valvate (Calotropis), twisted (china rose, lady's finger, cotton), imbricate (Cassia, gulmohur), vexillary (pea, bean: standard, 2 wings, 2 keel).
Stamens: epipetalous (brinjal), epiphyllous (lily); monadelphous (china rose), diadelphous (pea), polyadelphous (citrus); sterile = staminode. Carpels: apocarpous (lotus, rose), syncarpous (mustard, tomato). Placentation: marginal (pea), axile (china rose, tomato, lemon), parietal (mustard, Argemone), free central (Dianthus, primrose), basal (sunflower, marigold).
Fruit = ripened ovary; parthenocarpic without fertilisation; pericarp = epi-, meso-, endocarp; drupe: mango (edible mesocarp), coconut (fibrous mesocarp). Seed: testa + tegmen, hilum, micropyle; endospermic (castor) vs non-endospermous (bean, gram, pea); maize: aleurone, scutellum, coleoptile, coleorhiza. Solanaceae: ⊕ ⚥ K(5) C(5) A5 G(2), epipetalous, axile; potato's underground stem; tomato, brinjal, chilli, belladonna, ashwagandha, tobacco, petunia.

1. The root

In simple wordsPull up a mustard plant and you get a carrot-like main root with side branches. Pull up wheat and you get a beard of thin, equal roots. Look at a banyan and you see roots hanging from its branches. Three designs, three names: tap, fibrous, adventitious.

The underground part of a flowering plant is the root system; the part above ground is the shoot system. In most dicotyledons the radicle elongates directly into a primary root, which bears lateral roots of several orders (secondary, tertiary …); together they form the tap root system — as in mustard. In monocotyledons the primary root is short-lived and is replaced by many roots arising from the base of the stem — the fibrous root system, as in wheat. In plants like grass, Monstera and the banyan, roots arise from parts other than the radicle — adventitious roots. Roots absorb water and minerals, anchor the plant, store reserve food and synthesise plant growth regulators.

Tap, fibrous and adventitious roots — our schematic, not Figures 5.1–5.2 (pages 57–58).

Reading NCERT's Figures 5.1 and 5.2 (page 58)Figure 5.1, ‘Parts of a flowering plant’: a drawing of a mustard plant with yellow flowers and long pods, labelled flower, fruit, stem, leaf, node, internode and bud, with brackets marking the shoot system and the root system (primary and secondary roots). Figure 5.2, ‘Different types of roots’: photographs of (a) a tap root with a main root and laterals, (b) a tuft of fibrous roots, and (c) adventitious roots growing from the stem of a large-leaved climber. The point: tap and fibrous systems differ in where the roots come from — the radicle or the stem base.

The root apex is covered by a thimble-like root cap, which protects the tender tip as it pushes through soil. A few millimetres above it is the region of meristematic activity: very small, thin-walled cells with dense protoplasm that divide repeatedly. Cells above this region elongate and enlarge rapidly — the region of elongation, responsible for growth in length. They then differentiate and mature in the region of maturation, where some epidermal cells form fine, thread-like root hairs that absorb water and minerals.

Regions of the root tip — our schematic, not Figure 5.3 (page 59).

Reading NCERT's Figure 5.3 (page 59)‘The regions of the root-tip’: a tapering root with a pale pointed root cap, a dotted meristematic zone just behind it, a smooth pink elongation zone, and above it a bushy band of root hairs marking the region of maturation, each region bracketed. The point: root hairs appear only after cells stop elongating — absorption happens in the zone of maturation.

⤵ A root tip from the apex upward

Root capa thimble-like cover protects the tender apex as it pushes through soil

Meristematic regiona few millimetres above the cap: small, dense cells divide repeatedly

Region of elongationcells lengthen and enlarge rapidly — the root grows in length

Region of maturationcells differentiate; some epidermal cells form root hairs

Absorptionroot hairs take up water and minerals from the soil

Common confusions

Tap root = from the radicle (dicots); fibrous = from the stem base after the primary root dies (monocots). Both differ from adventitious roots, which arise from any part other than the radicle — the fibrous roots of wheat are, strictly, adventitious too (Beyond NCERT).
Root hairs absorb; they do not conduct (UPSC 1986). They form in the region of maturation, not of elongation.
Growth in length happens in the region of elongation; cell division in the meristematic region.
Roots also synthesise plant growth regulators — a function students often miss.

2. The stem and the leaf

In simple wordsA stem is the plant's scaffolding and plumbing: it holds leaves up to the light and carries water up and food around. A leaf is a solar panel on a stalk, and the way leaves are spaced on the stem — one, two or several per node — keeps them from shading one another.

The stem is the ascending part of the axis bearing branches, leaves, flowers and fruits. It develops from the plumule of the embryo. It bears nodes, where leaves arise, and internodes between them, and carries terminal or axillary buds. Young stems are generally green and later often woody and dark brown. The stem spreads out branches bearing leaves, flowers and fruits and conducts water, minerals and photosynthates; some stems also store food, give support or protection, or serve vegetative propagation.

The leaf is a lateral, generally flattened structure borne on the stem at a node, with a bud in its axil that later grows into a branch. Leaves originate from shoot apical meristems in acropetal order and are the main organs of photosynthesis. A typical leaf has a leaf base, a petiole and a lamina. The leaf base may bear two small leaf-like stipules; in monocots it expands into a sheath round the stem; in some legumes it swells into a pulvinus. The petiole holds the blade to light; long, thin, flexible petioles let blades flutter, cooling the leaf and bringing fresh air to its surface. The lamina has veins and veinlets, usually with a prominent midrib; veins give rigidity and carry water, minerals and food. Venation is reticulate when veinlets form a network (generally dicots) and parallel when veins run side by side (most monocots).

A leaf is simple when the lamina is entire or its incisions do not reach the midrib; compound when incisions reach the midrib, breaking the blade into leaflets. A bud lies in the axil of the petiole of both simple and compound leaves, but not in the axil of a leaflet. In a pinnately compound leaf, leaflets sit on a common axis, the rachis, which represents the midrib (neem); in a palmately compound leaf, leaflets attach at one point, the tip of the petiole (silk cotton).

Parts of a leaf, venation and compound leaves — our schematic, not Figures 5.4–5.5 (pages 59–61).

Reading NCERT's Figures 5.4 and 5.5 (page 60)Figure 5.4, ‘Structure of a leaf’: (a) a photographed leaf on a twig labelled lamina, petiole, stipule, leaf base and axillary bud; (b) a broad leaf with a net of veins (reticulate); (c) a long narrow leaf with veins running side by side (parallel). Figure 5.5, ‘Compound leaves’: (a) a neem leaf with paired leaflets along a labelled rachis; (b) a silk-cotton leaf with leaflets spreading like fingers from the petiole tip. The point: to tell a compound leaf from a twig with leaves, look for the axillary bud — it sits only at the base of the whole leaf.

Phyllotaxy is the pattern of leaves on a stem or branch: alternate — a single leaf at each node, alternately (china rose, mustard, sunflower); opposite — a pair at each node facing each other (Calotropis, guava); whorled — more than two at a node forming a whorl (Alstonia).

Alternate, opposite and whorled phyllotaxy — our schematic, not Figure 5.6 (page 61).

Reading NCERT's Figure 5.6 (page 61)‘Different types of phyllotaxy’: photographs of (a) a china-rose shoot with single leaves stepping up alternately, (b) a guava shoot with leaves in facing pairs, and (c) an Alstonia shoot with a rosette of long leaves from one node. The point: count the leaves at one node — one, two, or more than two.

Common confusions

The stem comes from the plumule, the root from the radicle.
A compound leaf has a bud only in the axil of its petiole, never of a leaflet — the test that separates it from a branch.
Pinnate = leaflets along a rachis (neem); palmate = leaflets from one point (silk cotton). Do not confuse with venation.
Reticulate venation is typical of dicots and parallel of monocots, but NCERT says ‘generally’ and ‘most’ — exceptions exist.
Pulvinus = swollen leaf base in some legumes; sheath = leaf base wrapping the stem in monocots; stipules = paired outgrowths of the leaf base.
Phyllotaxy: guava and Calotropis opposite; Alstonia whorled; china rose, mustard and sunflower alternate.

3. The inflorescence

In simple wordsPicture a queue. In one kind of flower cluster the queue keeps growing at the front — new buds keep appearing at the tip while the oldest flowers wait at the bottom (racemose). In the other, the tip itself becomes the first flower and closes the queue, so later flowers have to appear on side branches below it (cymose).

A flower is a modified shoot: the shoot apical meristem changes into a floral meristem, internodes do not elongate, the axis condenses, and the apex produces floral appendages laterally at successive nodes instead of leaves. A shoot tip that turns into a flower is always solitary. The arrangement of flowers on the floral axis is the inflorescence. If the main axis continues to grow and flowers are borne laterally in acropetal succession, the inflorescence is racemose. If the main axis ends in a flower and so is limited in growth, with flowers in basipetal order, it is cymose.

Racemose and cymose inflorescences, with the order in which flowers open — our schematic, not Figures 5.7–5.8 (pages 61–62).

⤵ From a shoot tip to a flower

Shoot apexthe shoot apical meristem normally makes leaves at nodes

Floral meristemthe apex is converted into a floral meristem

Condensed axisinternodes do not elongate, so the nodes crowd together

Floral appendagessepals, petals, stamens and carpels form at successive nodes instead of leaves

Inflorescence typeif the main apex keeps growing: racemose; if it becomes a flower: cymose

Reading NCERT's Figures 5.7 and 5.8 (pages 61–62)Figure 5.7, ‘Racemose inflorescence’: a photograph of a long spike of yellow flowers, open lower down and still in bud near the tip. Figure 5.8, ‘Cymose inflorescence’: a drawing of a branched stalk where each branch ends in a pink flower, with younger buds on side branches. The point: in racemose clusters the youngest buds are at the top; in cymose clusters the top flower is the oldest.

Common confusions

Racemose = acropetal (oldest at the base); cymose = basipetal (oldest at the apex).
In racemose the main axis has unlimited growth; in cymose it is limited because its apex becomes a flower.
Leaves too arise in acropetal order (section 2) — the same word, the same logic.
The flower is a modified shoot, not a modified leaf; its parts arise at condensed nodes.
Solanaceae's inflorescence is ‘solitary, axillary or cymose’ (section 8).

4. The flower: whorls, symmetry and ovary position

In simple wordsA flower is a shoot squashed flat into four rings: green protective sepals outside, showy petals next, pollen-making stamens, and egg-holding carpels in the middle. Botanists then ask: can it be cut into mirror halves in many ways or one? Are its parts in threes, fours or fives? And does the ovary sit on top of everything, in a cup, or sunk below?

The flower is the reproductive unit of angiosperms. A typical flower has four whorls on the swollen end of the stalk (pedicel), the thalamus or receptacle: calyx, corolla, androecium and gynoecium. Calyx and corolla are accessory organs; androecium and gynoecium are reproductive. In some flowers, such as lily, calyx and corolla are not distinct and are called the perianth. A flower with both androecium and gynoecium is bisexual; one with only stamens or only carpels is unisexual.

In symmetry a flower is actinomorphic (radial) if any radial plane through the centre divides it into two equal halves — mustard, datura, chilli; zygomorphic (bilateral) if only one particular vertical plane does — pea, gulmohur, bean, Cassia; and asymmetric (irregular) if no vertical plane does — canna. A flower is trimerous, tetramerous or pentamerous when its appendages are in multiples of 3, 4 or 5. Flowers with bracts — reduced leaves at the base of the pedicel — are bracteate; those without are ebracteate.

By the position of calyx, corolla and androecium relative to the ovary, flowers are hypogynous — the gynoecium is highest and other parts are below it, so the ovary is superior (mustard, china rose, brinjal); perigynous — the gynoecium is in the centre and other parts sit on the rim of the thalamus at almost the same level, so the ovary is half inferior (plum, rose, peach); or epigynous — the margin of the thalamus grows upward, encloses the ovary completely and fuses with it, and other parts arise above it, so the ovary is inferior (guava, cucumber, the ray florets of sunflower).

Hypogynous, perigynous and epigynous flowers — our longitudinal-section schematics, not Figure 5.9 (pages 62–63).

Reading NCERT's Figure 5.9 (page 62)‘Position of floral parts on thalamus’: four cut-away flowers — (a) a flower whose ovary sits on top with petals and stamens attached below it (hypogynous); (b) and (c) flowers whose thalamus forms a cup, petals and stamens on its rim around a central ovary (perigynous); (d) a flower whose ovary, full of ovules, is buried in the thalamus with the petals and stamens arising from its top (epigynous). The point: ‘superior’ and ‘inferior’ describe where the other parts join, relative to the ovary.

Reading NCERT's Figure 5.10 (page 63)‘Parts of a flower’: a pink flower with labels for androecium, gynoecium, corolla, calyx and pedicel, and beside it the parts laid out separately — a cluster of green sepals, five frilled petals, a bunch of stamens and a single slender pistil. The point: the four whorls are distinct organs that can be pulled apart and counted — the basis of a floral formula.

Feature	Terms	NCERT's examples
Sex	bisexual · unisexual	—
Symmetry	actinomorphic · zygomorphic · asymmetric	mustard, datura, chilli · pea, gulmohur, bean, Cassia · canna
Number of parts	trimerous · tetramerous · pentamerous	multiples of 3 · 4 · 5
Bracts	bracteate · ebracteate	—
Ovary position	hypogynous (superior) · perigynous (half inferior) · epigynous (inferior)	mustard, china rose, brinjal · plum, rose, peach · guava, cucumber, sunflower ray florets

Common confusions

Hypogynous ↔ superior ovary; epigynous ↔ inferior ovary. ‘Hypo-’ refers to the other parts lying below the gynoecium.
Perigynous = ovary half inferior — rose is NCERT's example here, while rose is also an example of apocarpous carpels (section 6).
Actinomorphic = radial (⊕); zygomorphic = bilateral (one plane); canna is asymmetric.
Perianth (lily) = calyx and corolla not distinguishable — not ‘no petals’.
Bract = a reduced leaf at the base of the pedicel, not a sepal.

5. Calyx, corolla and aestivation

In simple wordsBefore a flower opens, its petals are packed in the bud like the panels of a folded umbrella. Sometimes the edges just meet, sometimes each panel tucks under the next like a pinwheel, sometimes the overlap is jumbled — and in a pea the biggest petal wraps around all the others like a hood.

The calyx is the outermost whorl; its members, sepals, are generally green and leaf-like and protect the flower in bud. It may be gamosepalous (sepals united) or polysepalous (free). The corolla is made of petals, usually brightly coloured to attract insects for pollination; it may be gamopetalous (united) or polypetalous (free), and tubular, bell-shaped, funnel-shaped or wheel-shaped.

Aestivation is the arrangement of sepals or petals in the bud with respect to other members of the same whorl. Valvate: margins just touch without overlapping (Calotropis). Twisted: one margin of each appendage overlaps the next, and so on (china rose, lady's finger, cotton). Imbricate: margins overlap but in no particular direction (Cassia, gulmohur). Vexillary or papilionaceous: in pea and bean, of five petals the largest, the standard, overlaps the two lateral wings, which overlap the two smallest anterior petals, the keel.

Four kinds of aestivation, petals seen in a bud cross-section — our schematic, not Figure 5.11 (page 64).

Reading NCERT's Figure 5.11 (page 64)‘Types of aestivation in corolla’: for each type, a ring of curved lines (the petals in a cut bud) above a drawing of the orange-red bud itself — (a) valvate, edges meeting; (b) twisted, each petal tucked under the next; (c) imbricate, irregular overlaps; (d) vexillary, one large petal wrapping the rest. The point: the type is read from which margin lies on top.

Common confusions

Valvate — no overlap at all (Calotropis; also Solanaceae's calyx and corolla, section 8).
Twisted — overlap in one direction (china rose, cotton, lady's finger); imbricate — in no particular direction (Cassia, gulmohur).
Vexillary = papilionaceous: 1 standard + 2 wings + 2 keel = 5 petals; the standard is outermost, the keel innermost.
Cassia and gulmohur appear twice in NCERT: zygomorphic flowers and imbricate aestivation.
Gamo- = united, poly- = free — for sepals and petals alike.

6. Androecium, gynoecium and placentation

In simple wordsStamens are the flower's pollen factories; carpels are its seed nurseries. Botanists describe how stamens are joined (to each other, or to the petals) and how the ovules are seated inside the ovary — along a seam, on a central pillar, on the walls, or on a single cushion at the bottom.

The androecium is made of stamens, each a filament and an anther. An anther is usually bilobed, each lobe with two chambers, the pollen-sacs, where pollen grains form. A sterile stamen is a staminode. Stamens attached to petals are epipetalous (brinjal); attached to the perianth, epiphyllous (lily). Stamens may be free (polyandrous) or united: in one bundle, monadelphous (china rose); two bundles, diadelphous (pea); more than two, polyadelphous (citrus). Filament length may vary within a flower (Salvia, mustard).

Term	Meaning	NCERT's example
Epipetalous	stamens attached to petals	brinjal
Epiphyllous	stamens attached to the perianth	lily
Polyandrous	stamens free	—
Monadelphous	united in one bundle	china rose
Diadelphous	united in two bundles	pea
Polyadelphous	united in more than two bundles	citrus
Staminode	a sterile stamen	—

The gynoecium is the female part, of one or more carpels. A carpel has a stigma, a style and an ovary: the ovary is the enlarged base, the style an elongated tube connecting it to the stigma, which is the receptive surface for pollen. Each ovary bears one or more ovules on a flattened, cushion-like placenta. Free carpels are apocarpous (lotus, rose); fused carpels are syncarpous (mustard, tomato). After fertilisation the ovules become seeds and the ovary becomes the fruit.

Placentation is the arrangement of ovules within the ovary. Marginal: the placenta forms a ridge along the ventral suture and ovules form two rows on it (pea). Axile: the placenta is axial and ovules attach to it in a multilocular ovary (china rose, tomato, lemon). Parietal: ovules develop on the inner wall or periphery; the ovary is one-chambered but becomes two-chambered by a false septum (mustard, Argemone). Free central: ovules on a central axis with no septa (Dianthus, primrose). Basal: the placenta develops at the base of the ovary and bears a single ovule (sunflower, marigold).

Marginal, axile, parietal, free central and basal placentation — our schematics, not Figure 5.12 (page 65).

Reading NCERT's Figure 5.12 (page 65)‘Types of placentation’: (a) a green pea pod with seeds along one edge (marginal); (b) a round ovary divided into three chambers with ovules on the central axis (axile); (c) a one-chambered ovary with ovules on the wall (parietal); (d) a one-chambered ovary with a central cluster of ovules (free central); (e) a lengthwise section with a single ovule at the base (basal). The point: chambers + where the ovules attach decide the type — five drawn, though the text lists six names.

Common confusions

Axile needs a multilocular ovary with ovules on the central axis; free central has a central axis but no septa.
Parietal = ovules on the wall; mustard's ovary looks two-chambered only because of a false septum.
Basal = one ovule at the base (sunflower, marigold) — and sunflower's ray florets are epigynous (section 4).
Diadelphous = pea, monadelphous = china rose, polyadelphous = citrus; epipetalous = brinjal, epiphyllous = lily.
Apocarpous (lotus, rose) vs syncarpous (mustard, tomato) is about carpels; polyandrous vs adelphous is about stamens.
Stigma = the pollen-receiving tip of the carpel; saffron is dried stigmas (UPSC 2009, Beyond NCERT detail in lebo101).
NCERT slips: the placentation list names six types — ‘marginal, axile, parietal, basal, central and free central’ — but describes and draws only five; write the five. ‘Monoadelphous’ is a misprint for monadelphous. The false septum is characteristic of mustard (Beyond NCERT: Argemone's ovary is one-chambered without one), so give mustard as the example of a false septum.

7. The fruit and the seed

In simple wordsA fruit is a grown-up ovary, built like a house with three walls — skin, flesh, and an inner shell — around the seeds. A seed is a baby plant packed with a lunchbox: in a pea the lunch is in the two thick seed leaves; in a maize grain it sits in a separate bulky store, the endosperm.

The fruit is a characteristic feature of flowering plants: a mature or ripened ovary, developed after fertilisation. A fruit formed without fertilisation is parthenocarpic. A fruit has a wall, the pericarp, and seeds. The pericarp may be dry or fleshy; when thick and fleshy it is differentiated into the outer epicarp, middle mesocarp and inner endocarp. In mango and coconut the fruit is a drupe, developing from a monocarpellary superior ovary and one-seeded. In mango the pericarp has a thin epicarp, a fleshy edible mesocarp and a stony, hard endocarp; in coconut the mesocarp is fibrous.

Ovules become seeds after fertilisation. A seed is a seed coat and an embryo — a radicle, an embryonal axis and one cotyledon (wheat, maize) or two (gram, pea). In a dicot seed the seed coat has an outer testa and inner tegmen; the hilum is the scar where the seed was attached to the fruit, and above it is a small pore, the micropyle. Inside, the embryo has an embryonal axis and two often fleshy cotyledons full of reserve food, with the radicle and plumule at its two ends. In seeds such as castor the endosperm, formed by double fertilisation, stores food — endospermic seeds; in bean, gram and pea it is absent at maturity — non-endospermous.

Monocot seeds are generally endospermic, though some, such as orchids, are non-endospermic. In cereals such as maize, the seed coat is membranous and fused with the fruit wall. The endosperm is bulky and stores food; its outer covering, a proteinous aleurone layer, separates it from the embryo. The small embryo lies in a groove at one end of the endosperm: one large, shield-shaped cotyledon, the scutellum, and a short axis with a plumule and a radicle, sheathed by the coleoptile and the coleorhiza respectively.

A drupe, a dicot seed and a maize grain — our schematics, not Figures 5.13–5.15 (pages 65–67).

Reading NCERT's Figures 5.13–5.15 (pages 66–67)Figure 5.13, ‘Parts of a fruit’: (a) a mango cut lengthwise, labelled epicarp, mesocarp, seed and endocarp; (b) a photograph of a coconut split open to show the white kernel inside the brown fibrous husk. Figure 5.14, ‘Structure of dicotyledonous seed’: a brown bean-shaped seed with the hilum and micropyle marked, and the opened seed showing two yellow cotyledons with a small plumule and radicle between them. Figure 5.15, ‘Structure of a monocotyledonous seed’: a small whole grain marking endosperm and embryo, and a large lengthwise section labelled seed coat and fruit wall, aleurone layer, endosperm, scutellum, coleoptile, plumule, radicle and coleorhiza. The point: in a dicot seed the cotyledons store food; in a cereal grain the endosperm does, and the embryo is tucked to one side.

⤵ From flower to fruit and seed

Fertilisationmale gametes from pollen fertilise the ovules (details in lebo101)

Ovules → seedseach fertilised ovule becomes a seed: seed coat + embryo (± endosperm)

Ovary → fruitthe ovary wall becomes the pericarp: epicarp, mesocarp, endocarp

Without fertilisationa fruit may still form: a parthenocarpic fruit

	Dicot seed (gram, pea, bean)	Monocot seed (maize)
Cotyledons	two, often fleshy, store food	one, the shield-shaped scutellum
Endosperm	absent at maturity in bean, gram, pea (castor: present)	bulky; stores food; aleurone layer outside (orchids: none)
Seed coat	testa + tegmen; hilum and micropyle	membranous, fused with the fruit wall
Sheaths	—	coleoptile over the plumule, coleorhiza over the radicle

Common confusions

Fruit ← ovary; seed ← ovule (UPSC 1998 matched fruit–ovary and seed–ovule).
Parthenocarpic = fruit without fertilisation (seedless fruits; hormone treatment is in kebo113).
Mango's edible part is the mesocarp; coconut's mesocarp is the fibrous husk (Beyond NCERT: the coconut's edible white kernel and water are endosperm).
Castor is endospermic, a dicot exception; orchids are non-endospermic, a monocot exception.
Hilum = scar of attachment; micropyle = small pore above it.
Coleoptile sheathes the plumule; coleorhiza sheathes the radicle. Aleurone is proteinous.
NCERT's claim: drupes ‘develop from monocarpellary superior ovaries’. That fits mango; standard botany texts describe the coconut as coming from a three-carpelled ovary in which only one ovule develops (Beyond NCERT). For an exam, write that both are one-seeded drupes.

Why this matters for GS3Grain structure underlies food processing: polishing rice or refining wheat strips the bran and much of the aleurone layer, which is rich in protein (Beyond NCERT detail: also in minerals and B vitamins). Knowing which part of a crop is eaten — mesocarp of mango, endosperm of cereals, cotyledons of pulses — answers ‘edible part’ questions and links to nutrition and post-harvest policy.

8. Floral formula, floral diagram and the potato family

In simple wordsA floral formula is a flower written as a short code, like a chemical formula; a floral diagram is the same flower drawn as a bird's-eye map of its rings. With these two, a botanist in Delhi and one in Chennai can describe the same flower without a photograph.

A flowering plant is described briefly, in simple scientific language and in a fixed sequence: habit, then vegetative characters (roots, stem, leaves), then floral characters (inflorescence and flower parts), and finally a floral diagram and a floral formula. In the formula, Br = bracteate, K = calyx, C = corolla, P = perianth, A = androecium, G = gynoecium; G = superior ovary and G = inferior ovary; ♂ male, ♀ female, ⚥ bisexual; ⊕ actinomorphic and % zygomorphic. Fusion is shown by enclosing the number in brackets, and adhesion by a line drawn above the symbols of the floral parts. A floral diagram shows the number of parts, their arrangement and their relations; a dot at the top marks the position of the mother axis; calyx, corolla, androecium and gynoecium are drawn in successive whorls, calyx outermost and gynoecium in the centre.

A floral diagram of mustard and the floral-formula notation — our schematic, not Figures 5.16–5.17(f) (pages 67–69).

Reading NCERT's Figure 5.16 (page 67)‘Floral diagram with floral formula’: concentric rings — a green dot above for the mother axis, four hatched green sepals, four pale petals, six grey stamens and a central pink two-chambered ovary — with the formula ⊕ ⚥ K₂₊₂ C₄ A₂₊₄ G₍₂₎ beneath; the text identifies it as mustard (Brassicaceae). The point: count each ring from the diagram and you can write the formula — 4 sepals, 4 petals, 6 stamens, 2 fused carpels, superior ovary.

⤵ Writing a semi-technical description

Habitherb, shrub or tree

Vegetative charactersroot, then stem, then leaves (phyllotaxy, simple or compound, venation)

Inflorescenceracemose, cymose or solitary

Flowersex, symmetry; calyx, corolla (with aestivation), androecium, gynoecium (with placentation)

Summarydraw the floral diagram and write the floral formula

5.9 Solanaceae — the ‘potato family’ — is a large family spread through the tropics, subtropics and even temperate zones. Vegetative characters: mostly herbs and shrubs, rarely small trees. Stem herbaceous, rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous; an underground stem in potato (Solanum tuberosum). Leaves alternate, simple, rarely pinnately compound, exstipulate; venation reticulate. Floral characters: inflorescence solitary, axillary or cymose as in Solanum; flower bisexual, actinomorphic; calyx of five united, persistent sepals, valvate; corolla of five united petals, valvate; androecium of five epipetalous stamens; gynoecium bicarpellary, obliquely placed, syncarpous; ovary superior, bilocular, with a swollen placenta bearing many ovules, axile. Fruit a berry or capsule; seeds many, endospermous. Floral formula: ⊕ ⚥ K₍₅₎ C₍₅₎ A₅ G₍₂₎, with a line above C and A for the epipetalous stamens.

Use (NCERT)	Plants of the potato family
Food	tomato, brinjal, potato
Spice	chilli
Medicine	belladonna, ashwagandha
Fumigatory	tobacco
Ornamental	petunia

Reading NCERT's Figure 5.17 (page 68)‘Solanum nigrum (makoi) plant’: (a) a flowering twig with broad, toothed leaves, small white star-shaped flowers and red-and-black berries; (b) a single flower; (c) a lengthwise section of the flower; (d) the five stamens in a ring; (e) a carpel with a swollen ovary and a short style; (f) its floral diagram — a five-sided calyx, five petals, five stamens and a two-chambered ovary full of ovules. The point: every line of the family description can be checked against a real flower — five fused petals, stamens on the petals, axile placentation.

Common confusions

G (line below) = superior; G (line above) = inferior.
Brackets = fusion within a whorl (cohesion); a line above two whorls = fusion between whorls (adhesion, e.g. epipetalous).
Mustard: K₂₊₂ C₄ A₂₊₄ G₍₂₎ — tetramerous, 6 stamens (2 short + 4 long, Beyond NCERT: ‘tetradynamous’), parietal placentation with a false septum.
Solanaceae: pentamerous, valvate calyx and corolla, epipetalous stamens, bicarpellary syncarpous superior ovary, axile; fruit a berry or capsule.
Potato is a stem (an underground stem — UPSC 1996), not a root; sweet potato and carrot are roots (Beyond the reprint, section 9).
NCERT slip: ‘bicarpellary obligately placed’ is a misprint for obliquely placed — the two carpels sit at an angle to the flower's midline.

Beyond NCERT: GM vegetables of the potato familyBrinjal, tomato and potato are among the most researched crops for genetic modification. Bt brinjal, engineered to resist the fruit-and-shoot borer, was put under a moratorium on commercial release in India in 2010; the technology itself is taught in lebo110. Positions on such crops are stated below by their holders, with no verdict here.

Position	Held by	Main argument
Allow GM vegetables after regulatory testing	crop developers and many agricultural scientists	less insecticide use, lower losses to pests, higher farm income
Keep a moratorium or reject them	many farmer groups, environmental groups and some scientists	uncertain health and biodiversity effects, gene flow to wild relatives (India is a centre of brinjal diversity), seed-company dependence

Why this matters for GS3The potato family joins food security (potato, tomato, brinjal), spices (chilli), the drug trade (belladonna, and ashwagandha in AYUSH systems), public health (tobacco) and biotechnology regulation (Bt brinjal). Floral formulae and family characters are also how plant taxonomists confirm the identity of medicinal plants in trade.

9. Modifications of root, stem and leaf (Beyond the reprint)

In simple wordsPlant organs take odd jobs. A carrot is a root turned into a larder; a potato is a stem gone underground to store food; the curly tendril of a pea is a leaf turned into a hook. The test is always where the part comes from, not what it looks like.

Beyond NCERT — from earlier editionsThe 2026-27 reprint dropped the sections on modified roots, stems and leaves, but its own Summary still says roots get ‘modified for storage of food, mechanical support and respiration’, the chapter opening mentions adaptations for ‘protection, climbing, storage’, and the reprint keeps potato's underground stem. Earlier editions of this chapter gave the examples below. The rule for identifying a modified organ: a stem has nodes, internodes and buds (eyes of a potato are buds); a root has none; a leaf arises at a node with a bud in its axil.

Organ	Modified for	Examples (earlier NCERT editions)
Root	food storage	tap roots of carrot and turnip; adventitious roots of sweet potato
Root	mechanical support	prop roots hanging from the branches of the banyan; stilt roots from the lower nodes of maize and sugarcane
Root	respiration	roots growing upward out of swampy soil in mangroves such as Rhizophora (pneumatophores)
Stem	food storage (underground)	potato, ginger, turmeric, zaminkand, Colocasia
Stem	climbing	tendrils from axillary buds in cucumber, pumpkins, watermelon, grapevine
Stem	protection	thorns from axillary buds in Citrus, Bougainvillea
Stem	photosynthesis in arid regions	flattened stem of Opuntia; fleshy cylindrical stem of Euphorbia
Stem	vegetative spread	runners in grass and strawberry; stolons in mint and jasmine; offsets in Pistia and Eichhornia
Leaf	climbing	tendrils in pea
Leaf	defence / less water loss	spines in cacti
Leaf	food storage	fleshy leaves of onion and garlic
Leaf	photosynthesis	flattened petioles (phyllodes) in Australian Acacia
Leaf	trapping insects	pitcher plant, Venus fly-trap

Common confusions

Potato = stem, sweet potato = root, carrot = root (UPSC 1996).
Turmeric and ginger are underground stems (rhizomes), not roots (UPSC 1983).
The pitcher of a pitcher plant is a modified leaf (UPSC 2007).
Tendrils can be stem (cucumber, grapevine) or leaf (pea); thorns are stems (Citrus, Bougainvillea), spines are leaves (cacti).
Onion stores food in fleshy leaves; its stem is a small disc at the base (Beyond NCERT).
Banyan's hanging roots are prop roots; maize's are stilt roots; both are adventitious.

Why this matters for Prelims and GS3Questions on ‘which part of the plant is eaten’ (potato, turmeric, ginger, onion, sweet potato) recur; mangrove breathing roots tie into coastal ecology; stem cuttings, runners and offsets underlie vegetative propagation in horticulture; water hyacinth (Eichhornia) spreads by offsets and is an invasive weed of Indian water bodies.

NCERT's in-text questions

The running text asks one question — ‘What are the features that distinguish a stem from a root?’ (page 59) — and has no activities.

What are the features that distinguish a stem from a root?

A stem develops from the plumule, grows upward, bears nodes and internodes, buds (terminal and axillary), leaves, flowers and fruits, and is generally green when young; the Summary adds multicellular hairs and positive phototropism. A root develops from the radicle (or arises adventitiously), grows into the soil, has a root cap, unicellular root hairs and no nodes, internodes, leaves or buds.

NCERT exercise — answer outlines

Reading NCERT's Summary and Exercises (pages 69–70)The Summary recaps the root and shoot systems, leaf variation, the flower as a modified shoot and its variations, fruit and seed, and floral diagrams and formulae for describing families. Ten exercises follow. The point: two Summary lines reach beyond the reprint — modified roots (section 9 here) and stems' multicellular hairs and positive phototropism, which the stem section never mentions; and ‘leaf … developed exogenously’ means the leaf arises from the outer tissues of the shoot apex (Beyond NCERT).

1. How is a pinnately compound leaf different from a palmately compound leaf?

Pinnately compound: leaflets borne along a common axis, the rachis, which represents the midrib (neem). Palmately compound: leaflets attached at one common point, the tip of the petiole (silk cotton). In both, a bud is present in the axil of the petiole, not of the leaflets.

2. Explain with suitable examples the different types of phyllotaxy.

Phyllotaxy is the arrangement of leaves on the stem. Alternate: one leaf per node, alternately (china rose, mustard, sunflower). Opposite: a pair of leaves per node facing each other (Calotropis, guava). Whorled: more than two leaves per node forming a whorl (Alstonia).

3. Define the following terms: (a) aestivation (b) placentation (c) actinomorphic (d) zygomorphic (e) superior ovary (f) perigynous flower (g) epipetalous stamen

(a) Aestivation: the arrangement of sepals or petals in the bud relative to others of the same whorl (valvate, twisted, imbricate, vexillary). (b) Placentation: the arrangement of ovules within the ovary (marginal, axile, parietal, free central, basal). (c) Actinomorphic: divisible into two equal halves by any radial plane through the centre (mustard, datura, chilli). (d) Zygomorphic: divisible into similar halves in only one vertical plane (pea, gulmohur, bean, Cassia). (e) Superior ovary: the gynoecium sits highest on the thalamus, other parts below it — a hypogynous flower (mustard, china rose, brinjal). (f) Perigynous flower: the gynoecium is central and other parts arise on the rim of the thalamus at about the same level; ovary half inferior (plum, rose, peach). (g) Epipetalous stamen: a stamen attached to a petal (brinjal; Solanaceae).

4. Differentiate between (a) Racemose and cymose inflorescence (b) Apocarpous and syncarpous ovary

(a) Racemose: main axis continues to grow; flowers lateral, in acropetal succession (oldest at the base). Cymose: main axis ends in a flower, so growth is limited; flowers in basipetal order (oldest at the top). (b) Apocarpous: more than one carpel, free (lotus, rose). Syncarpous: carpels fused (mustard, tomato).

5. Draw the labelled diagram of the following: (i) gram seed (ii) V.S. of maize seed

(i) Gram seed (dicot): label seed coat (testa, tegmen), hilum, micropyle; open it to show two cotyledons, the embryonal axis, plumule and radicle (no endosperm at maturity). (ii) V.S. of maize: label seed coat and fruit wall (fused), aleurone layer, endosperm, scutellum, coleoptile, plumule, radicle and coleorhiza. Practise with the schematic in section 7.

6. Take one flower of the family Solanaceae and write its semi-technical description. Also draw their floral diagram.

E.g. brinjal or Solanum nigrum: herb/shrub; leaves alternate, simple, exstipulate, reticulate. Inflorescence solitary, axillary or cymose. Flower bisexual, actinomorphic, pentamerous; calyx 5, united, persistent, valvate; corolla 5, united, valvate; androecium 5, epipetalous; gynoecium bicarpellary, obliquely placed, syncarpous, ovary superior, bilocular, swollen axile placenta with many ovules. Fruit berry; seeds many, endospermous. Formula ⊕ ⚥ K₍₅₎ C₍₅₎ A₅ G₍₂₎ with a line over C and A. Floral diagram: mother-axis dot at top; rings of 5 sepals, 5 petals, 5 stamens alternating with petals; a central two-chambered ovary with ovules on the swollen axis.

7. Describe the various types of placentations found in flowering plants.

Marginal — a ridge along the ventral suture, ovules in two rows (pea). Axile — ovules on the central axis of a multilocular ovary (china rose, tomato, lemon). Parietal — ovules on the inner wall of a one-chambered ovary, which may become two-chambered by a false septum (mustard, Argemone). Free central — ovules on a central axis without septa (Dianthus, primrose). Basal — a single ovule at the base of the ovary (sunflower, marigold).

8. What is a flower? Describe the parts of a typical angiosperm flower.

A flower is the reproductive unit of angiosperms — a modified shoot whose apical meristem became a floral meristem, with a condensed axis bearing floral appendages. On the thalamus are four whorls: calyx (sepals, green, protective; gamo- or polysepalous), corolla (petals, coloured, attract pollinators; gamo- or polypetalous), androecium (stamens: filament + bilobed anther with four pollen-sacs) and gynoecium (carpels: stigma, style, ovary with ovules on a placenta). Calyx and corolla are accessory; androecium and gynoecium reproductive.

9. Define the term inflorescence. Explain the basis for the different types inflorescence in flowering plants.

The inflorescence is the arrangement of flowers on the floral axis. The basis is whether the apex of the main axis becomes a flower or keeps growing: if it keeps growing, flowers arise laterally in acropetal order — racemose; if it ends in a flower, growth is limited and flowers arise in basipetal order — cymose.

10. Describe the arrangement of floral members in relation to their insertion on thalamus.

Hypogynous: gynoecium highest; calyx, corolla and androecium inserted below it; ovary superior (mustard, china rose, brinjal). Perigynous: gynoecium central; other parts on the rim of a cup-shaped thalamus at about the same level; ovary half inferior (plum, rose, peach). Epigynous: thalamus grows up round the ovary and fuses with it; other parts arise above the ovary; ovary inferior (guava, cucumber, sunflower ray florets).

What to remember

Numbers

Chapter pages57–70 (9 sections, 17 figures, 10 exercises); PDF also has the Unit II opener and Esau box (55–56)

Root systems3 — tap, fibrous, adventitious

Regions of a root tip4 — cap, meristematic, elongation, maturation

Main parts of a leaf3 — leaf base, petiole, lamina

Types of phyllotaxy3 — alternate (1/node), opposite (2), whorled (more than 2)

Floral whorls4 — 2 accessory (calyx, corolla), 2 reproductive

Merous flowerstrimerous 3 · tetramerous 4 · pentamerous 5

Aestivation types4 — valvate, twisted, imbricate, vexillary

Vexillary petals5 — 1 standard, 2 wings, 2 keel

Pollen-sacs per anther4 (2 lobes × 2 chambers)

Parts of a carpel3 — stigma, style, ovary

Placentation types described5 (the list names 6)

Pericarp layers3 — epicarp, mesocarp, endocarp

Seed-coat layers2 — testa, tegmen

Mustard formula⊕ ⚥ K2+2 C4 A2+4 G(2) — 4 sepals, 4 petals, 6 stamens, 2 carpels

Solanaceae formula⊕ ⚥ K(5) C(5) A5 G(2) — epipetalous, superior

Katherine Esau1898–1997; Plant Anatomy 1954; Anatomy of Seed Plants 1960; NAS 1957; Medal 1989

One-liners

Mustard has a tap root; wheat has fibrous roots.
Banyan, Monstera and grass have adventitious roots.
Root hairs arise in the region of maturation and absorb water and minerals.
The stem develops from the plumule.
A swollen leaf base in some legumes is the pulvinus.
The rachis of a pinnately compound leaf represents the midrib.
Silk cotton has a palmately compound leaf; neem a pinnately compound one.
Alstonia shows whorled phyllotaxy; guava and Calotropis opposite.
A flower is a modified shoot.
Racemose inflorescences grow acropetally; cymose ones basipetally.
Lily has a perianth and epiphyllous stamens.
Canna flowers are asymmetric.
Plum, rose and peach flowers are perigynous.
Guava, cucumber and sunflower ray florets have an inferior ovary.
China rose has twisted aestivation and monadelphous stamens.
Pea has vexillary aestivation, diadelphous stamens and marginal placentation.
Citrus stamens are polyadelphous.
A sterile stamen is a staminode.
Lotus and rose have apocarpous carpels.
Tomato and lemon have axile placentation.
Sunflower and marigold have basal placentation.
A fruit formed without fertilisation is parthenocarpic.
Mango and coconut are drupes.
Castor seeds are endospermic; bean, gram and pea seeds are not.
The scutellum is the single cotyledon of maize.
Potato is an underground stem of the family Solanaceae.

Traps to avoid

Root hairs absorb; they do not conduct.
A bud lies in the axil of a petiole, never of a leaflet.
Hypogynous means superior ovary; epigynous means inferior ovary.
Twisted overlap runs one way; imbricate has no fixed direction.
The vexillary standard is outermost; the keel innermost.
Axile placentation needs septa; free central has none.
Mustard's two chambers come from a false septum.
Fruit comes from the ovary; seed from the ovule.
Mango's edible part is the mesocarp.
Coleoptile covers the plumule; coleorhiza covers the radicle.
G underlined is superior; G overlined is inferior.
Potato and turmeric are stems; sweet potato and carrot are roots.
NCERT lists six placentation names but describes five.
'Obligately placed' should read 'obliquely placed'.
'Monoadelphous' should read 'monadelphous'.

How to strategise

Prelims — what UPSC asks

Asked so far: root hairs absorb, they do not conduct (1986); potato is a modified stem (1996); fruit–ovary, seed–ovule (1998); saffron is the stigma (2009); and, from the modifications earlier editions taught (section 9 here), turmeric is a stem (1983) and the pitcher is a leaf (2007).
Key note: in 1986 (‘main root — storage, lateral root — absorption, root hair — conduction’) the key is (a) ‘only A’. Root hairs certainly do not conduct, but lateral roots do absorb through the root hairs they bear, so statement B is arguable — treat the key as disputed and remember NCERT's line that root hairs absorb water and minerals.
Likely next: which part of a crop is a stem, root or leaf; edible parts (mesocarp, endosperm, cotyledons); flower parts used as products (stigma, petals, buds); inflorescence types; ovary position; placentation in common fruits; endospermic vs non-endospermic seeds; members and uses of the potato family; Bt brinjal and other GM vegetables.

Mains — where it appears and how to answer

GS3 Agriculture / Science & Technology: no Mains question has been set on this chapter. Use it for answers on horticulture and propagation (stem cuttings, tubers, runners), grain structure and food processing, the potato family in food and drug economies, GM crop regulation (with positions attributed) and medicinal-plant identification.

Self-check

Tap an option. NCERT's own exercise questions come first; the rest test the figures and common confusions.

1. Root hairs develop from the epidermis in the:

2. Opposite phyllotaxy is seen in:

3. In a cymose inflorescence:

4. A flower whose ovary is half inferior is:

5. Vexillary aestivation and diadelphous stamens occur together in:

6. Ovules on a central axis in a multilocular ovary is:

7. The edible part of a mango is the:

8. Which is the correct floral formula feature of Solanaceae?

UPSC questions from this chapter

Open any question to attempt it in the Question bank — your attempt is saved to your progress.

Prelims

4 questions · newest first

2009Prelims GSIn making the saffron spice, which one of the following parts of the plant is used ?Attempt →1998Prelims GSMatch List I with List II and select the correct answer using the codes given below the lists : Codes: List I List II I. Fruit (A) Ovule II. Seed (B) Leaf III. Wood (C) Stem IV. Starch (D) OvaryAttempt →1996Prelims GSWhich one of the following is a modified stem ?Attempt →1986Prelims GSWhich of the following pairs is/are correct ? (A) Main root — Storage (B) Lateral root — Absorption (C) Root hair — ConductionAttempt →

Mains

0 questions

4 Prelims and 0 Mains UPSC questions are linked to this chapter. More from Biology.