Morphology of Flowering Plants Class 11 Biology: Root to Seed and Family Solanaceae

What Morphology of Flowering Plants is about

Weightage: This chapter is part of Unit II, Structural Organization in Plants and Animals, which carries 10 of the 70 theory marks in the school annual exam together with Anatomy of Flowering Plants and Structural Organisation in Animals.Source: CBSE Biology (044) syllabus 2026-27, Class XI course structure, Unit II Structural Organization in Plants and Animals

Key concepts

The root and its regions

NCERT section 5.1 The Root (5.1.1 Regions of the Root)

In most dicots, the radicle (embryonic root) elongates directly into the primary root, which grows inside the soil and bears lateral roots of several orders (secondary, tertiary). The primary root and its branches form the tap root system, e.g. mustard.

In monocots, the primary root does not last long; many roots grow from the base of the stem in its place: the fibrous root system, e.g. wheat.

In some plants, roots arise from parts other than the radicle: adventitious roots, e.g. grass, *Monstera* and the banyan tree.

Functions: absorption of water and minerals, anchorage, storage of reserve food, and synthesis of plant growth regulators.

Regions of the root (from the tip upwards):
1. Root cap: a thimble-like structure covering the apex, protecting the tender tip as it pushes through soil.
2. Region of meristematic activity: a few millimetres above the cap; small, thin-walled cells with dense protoplasm that divide repeatedly.
3. Region of elongation: cells just behind it elongate rapidly and enlarge, increasing root length.
4. Region of maturation: cells gradually differentiate and mature. Some epidermal cells here form very fine, thread-like root hairs, which absorb water and minerals from the soil.

Worked example

Distinguish between tap root and fibrous root systems with an example each, and name the region of the root that bears root hairs. (3 marks)

Try it first, then show the solutionSolution

1. Tap root: the radicle grows into a primary root that persists and bears lateral branches; e.g. mustard (dicots). (1)
2. Fibrous root: the primary root is short-lived and replaced by many roots from the stem base; e.g. wheat (monocots). (1)
3. Root hairs arise in the region of maturation. (1)

Answer: Tap root (mustard) vs fibrous root (wheat); root hairs in the zone of maturation.

The stem

NCERT section 5.2 The Stem

The stem is the upward-growing axis of the plant that carries branches, leaves, flowers and fruits. It grows out of the plumule when a seed germinates.

Features:

• It bears nodes (where leaves are borne) and internodes (portions between two nodes).
• It bears buds, which may be terminal (at the tip) or axillary (in the angle between leaf and stem).
• It is generally green when young and later often becomes woody and dark brown.

Functions:

• Main: spreading out branches bearing leaves, flowers and fruits; conducting water, minerals and photosynthates.
• Others: storage of food, support, protection and vegetative propagation in some plants.

(The modified underground and aerial stems, such as potato tubers or tendrils, are not in the 2026-27 syllabus.)

Worked example

How would you distinguish a stem from a root using external features? Give three points. (3 marks)

Try it first, then show the solutionSolution

1. The stem develops from the plumule; the root from the radicle. (1)
2. The stem has nodes and internodes and bears leaves and buds; the root has no nodes, internodes, leaves or buds. (1)
3. The stem is usually green when young and grows towards light; the root is non-green and grows into the soil, with a root cap and root hairs. (1)

Answer: Origin (plumule vs radicle), nodes and buds, and colour/root cap and hairs.

The leaf: parts, venation, types and phyllotaxy

NCERT section 5.3 The Leaf (5.3.1 Venation, 5.3.2 Types of Leaves, 5.3.3 Phyllotaxy)

A leaf is a flat outgrowth on the side of the stem, arising at a node with a bud in its axil that can later grow into a branch. Leaves are formed by the shoot apical meristem in acropetal order (younger ones towards the tip), and they are the plant's main organs of photosynthesis.

Parts:
1. Leaf base: attaches the leaf to the stem; may bear two small lateral leaf-like stipules. In monocots the leaf base expands into a sheath covering the stem partly or wholly; in some legumes the base may become swollen (pulvinus).
2. Petiole: holds the blade to light; long, thin, flexible petioles let the blade flutter in wind, cooling the leaf and bringing fresh air.
3. Lamina (leaf blade): the green, expanded part with veins and veinlets; the prominent middle vein is the midrib. Veins give rigidity and act as channels for water, minerals and food.

Venation (arrangement of veins and veinlets):

• Reticulate: veinlets form a network; typical of dicots.
• Parallel: veins run parallel to each other; typical of monocots.

Types of leaves:

• Simple: the lamina is entire, or if incised, the incisions do not reach the midrib.
• Compound: incisions reach the midrib, breaking the lamina into leaflets. A bud is present in the axil of the petiole of both simple and compound leaves, but not in the axil of leaflets.
• Pinnately compound: leaflets on a common axis, the rachis (the midrib), e.g. neem.
• Palmately compound: leaflets attached at a common point, the tip of the petiole, e.g. silk cotton.

Phyllotaxy (arrangement of leaves on the stem or branch):

• Alternate: a single leaf at each node in alternate manner (china rose, mustard, sunflower).
• Opposite: a pair of leaves at each node, opposite each other (*Calotropis*, guava).
• Whorled: more than two leaves at a node, forming a whorl (*Alstonia*).

Worked example

Name the leaf part described and state its role or occurrence: (a) two small leaf-like outgrowths at the leaf base (b) a leaf base expanded to wrap partly or wholly round the stem (c) a swollen leaf base. What venation would you expect in a grass leaf, and why? (3 marks)

Try it first, then show the solutionSolution

1. (a) Stipules, lateral outgrowths of the leaf base. (b) A leaf sheath, typical of monocots. (1)
2. (c) Pulvinus, seen in some leguminous plants. (1)
3. Grass is a monocot, so its leaves show parallel venation: the veins run parallel to each other along the blade. (1)

Answer: (a) stipules (b) sheath (monocots) (c) pulvinus (legumes); grass has parallel venation because it is a monocot.

Inflorescence

NCERT section 5.4 The Inflorescence

A flower is a modified shoot: its apical meristem turns into a floral meristem, the internodes stay short so the axis is compressed, and the nodes carry floral parts in place of leaves.

A shoot tip that turns into a flower gives a single, solitary flower. The way flowers are arranged on a floral axis is called the inflorescence. Depending on whether the apex develops into a flower or continues to grow, there are two main types:

• Racemose: the main axis continues to grow, and flowers are borne laterally in acropetal succession (older flowers at the base, younger towards the tip).
• Cymose: the main axis terminates in a flower and so is limited in growth; flowers are borne in basipetal order (older flower at the tip, younger ones lower down).

Worked example

On plant X, the lowest flowers on the axis are open, the buds near the tip are still closed and the tip keeps growing. On plant Y, the axis ends in an open flower and the younger buds lie below it. Name the inflorescence of each and explain your decision. Why is a single flower borne at a shoot tip not called an inflorescence? (3 marks)

Try it first, then show the solutionSolution

1. X: racemose; the axis is unlimited and flowers open in acropetal succession (oldest at the base). (1)
2. Y: cymose; the axis is limited because its apex has become a flower, and flowers develop in basipetal order (oldest at the tip). (1)
3. An inflorescence is the arrangement of several flowers on a floral axis; a shoot tip that turns into one flower gives a solitary flower, so there is no arrangement to describe. (1)

Answer: X racemose (unlimited axis, acropetal); Y cymose (axis ends in a flower, basipetal); a solitary flower is not an arrangement of flowers.

The flower: symmetry, whorls and position of floral parts

NCERT section 5.5 The Flower

The flower is the reproductive unit of angiosperms, meant for sexual reproduction. 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 organs. In some flowers (lily), calyx and corolla are not distinct and are called perianth.

• Bisexual flowers have both androecium and gynoecium; unisexual flowers have only one.
• Symmetry: actinomorphic (radial symmetry; can be divided into two equal halves by any radial plane through the centre: mustard, datura, chilli); zygomorphic (bilateral; divided into two similar halves only in one particular vertical plane: pea, gulmohur, bean, *Cassia*); asymmetric (irregular; cannot be divided by any vertical plane: canna).
• Trimerous, tetramerous, pentamerous: floral appendages in multiples of 3, 4 or 5.
• Bracteate flowers have small reduced leaves (bracts) at the base of the pedicel; ebracteate flowers lack them.

Position of floral parts relative to the ovary on the thalamus:

• Hypogynous: the gynoecium is at the highest position and the other parts are below it; the ovary is superior (mustard, china rose, brinjal).
• Perigynous: the gynoecium is in the centre and other parts are on the rim of the thalamus at almost the same level; the ovary is half-inferior (plum, rose, peach).
• Epigynous: the margin of the thalamus grows upward, enclosing the ovary completely and fusing with it; other parts arise above the ovary, which is inferior (guava, cucumber, ray florets of sunflower).

Worked example

Classify the flowers of (a) mustard (b) rose (c) guava as hypogynous, perigynous or epigynous, and state the position of the ovary in each. (3 marks)

Try it first, then show the solutionSolution

1. (a) Mustard: hypogynous; ovary superior. (1)
2. (b) Rose: perigynous; ovary half-inferior. (1)
3. (c) Guava: epigynous; ovary inferior. (1)

Answer: Mustard hypogynous (superior), rose perigynous (half-inferior), guava epigynous (inferior).

Parts of a flower: calyx, corolla, aestivation, androecium, gynoecium and placentation

NCERT section 5.5.1 Parts of a Flower (calyx, corolla, aestivation, androecium, gynoecium, placentation)

Calyx: outermost whorl; its members are sepals, generally green and leaf-like, protecting the flower in the bud. Gamosepalous (sepals united) or polysepalous (free).

Corolla: petals, usually brightly coloured to attract insects for pollination. Gamopetalous or polypetalous. The corolla can be tube-like, bell-like, funnel-like or wheel-like.

Aestivation: how the sepals or petals of one whorl are arranged relative to each other inside the bud.

• Valvate: margins just touch without overlapping (*Calotropis*).
• Twisted: one margin of each appendage overlaps the next one (china rose, lady's finger, cotton).
• Imbricate: margins overlap one another but not in any particular direction (*Cassia*, gulmohur).
• Vexillary (papilionaceous): in pea and bean, the biggest petal (standard) covers the two side petals (wings), and these cover the two smallest front petals that form the keel.

Androecium: stamens (male organs), each with a stalk (filament) and an anther (usually bilobed, each lobe with two chambers, pollen sacs). A sterile stamen is a staminode. Stamens may be attached to petals (epipetalous, brinjal) or to the perianth (epiphyllous, lily). Free stamens are polyandrous; united stamens may form one bundle (monoadelphous, china rose), two bundles (diadelphous, pea) or more (polyadelphous, citrus). Filament lengths may vary within a flower (*Salvia*, mustard).

Gynoecium: carpels (female organs). Each carpel has a stigma (receives pollen), a style (elongated tube) and an ovary (enlarged basal part) bearing ovules on a cushion-like placenta. Free carpels: apocarpous (lotus, rose); fused: syncarpous (mustard, tomato). After fertilisation, ovules become seeds and the ovary matures into a fruit.

Placentation (arrangement of ovules within the ovary):

• Marginal: placenta as a ridge along the ventral suture of a one-chambered ovary, with ovules in two rows (pea).
• Axile: placenta axial, ovules attached to it in a multilocular ovary (china rose, tomato, lemon).
• Parietal: ovules on the inner wall or peripheral part of the ovary; one-chambered but becomes two-chambered by a false septum (mustard, *Argemone*).
• Free central: ovules on a central axis and septa absent (*Dianthus*, primrose).
• Basal: placenta at the base of the ovary with a single ovule attached (sunflower, marigold).

Worked example

Name the placentation and give one example: (a) a one-chambered ovary with ovules in two rows along one ridge (b) ovules borne on a central column with no septa (c) a single ovule attached at the base of the ovary. (3 marks)

Try it first, then show the solutionSolution

1. (a) Marginal: the placenta forms a ridge along the ventral suture; e.g. pea. (1)
2. (b) Free central: ovules on a central axis, septa absent; e.g. Dianthus or primrose. (1)
3. (c) Basal: the placenta is at the base and bears a single ovule; e.g. sunflower or marigold. (1)

Answer: (a) marginal (pea) (b) free central (Dianthus) (c) basal (sunflower)

The fruit and the seed

NCERT section 5.6 The Fruit; 5.7 The Seed (5.7.1 Dicotyledonous, 5.7.2 Monocotyledonous)

Fruit: a characteristic feature of flowering plants; it is a mature or ripened ovary formed after fertilisation. A fruit formed without fertilisation is a parthenocarpic fruit.

A fruit has a wall (pericarp) and seeds. A thick, fleshy pericarp is differentiated into an outer epicarp, a middle mesocarp and an inner endocarp.

In mango and coconut, the fruit is a drupe: developed from a monocarpellary superior ovary and one-seeded. In mango, the epicarp is thin, the mesocarp is fleshy and edible, and the endocarp is stony and hard. In coconut, the mesocarp is fibrous.

Seed: ovules develop into seeds after fertilisation. A seed has a seed coat and an embryo; the embryo has a radicle, an embryonal axis and one (wheat, maize) or two (gram, pea) cotyledons.

Dicotyledonous seed (e.g. bean, gram, pea):

• Seed coat with two layers: outer testa and inner tegmen.
• Hilum: a scar where the seed was attached to the fruit. Micropyle: a small pore above the hilum.
• Embryo: embryonal axis with radicle and plumule at its two ends, and two fleshy cotyledons full of reserve food.
• In some seeds (castor), food is stored in the endosperm (formed by double fertilisation); in bean, gram and pea the endosperm is absent in the mature seed (non-endospermous).

Monocotyledonous seed (e.g. maize):

• Generally endospermic (some, like orchids, are non-endospermic).
• A thin, membrane-like seed coat is usually joined to the fruit wall.
• Most of the grain is a large food-storing endosperm. Its outer covering is a proteinous layer called the aleurone layer.
• The embryo is small, in a groove at one end of the endosperm. It has one large, shield-shaped cotyledon, the scutellum, and a short axis with a plumule and radicle. The plumule and radicle are enclosed in sheaths: coleoptile and coleorhiza.

Worked example

Name the parts of the mango fruit's pericarp and state which is edible. How does the coconut differ? (2 marks)

Try it first, then show the solutionSolution

1. Mango (drupe): thin epicarp, fleshy edible mesocarp, stony hard endocarp. (1)
2. Coconut is also a drupe, but its mesocarp is fibrous. (1)

Answer: Epicarp, edible mesocarp, stony endocarp; coconut has a fibrous mesocarp.

Semi-technical description and family Solanaceae

NCERT section 5.8 Semi-technical Description of a Typical Flowering Plant; 5.9 Solanaceae

A flowering plant is described in a set order: habit, vegetative characters (roots, stem, leaves), then floral characters (inflorescence and flower parts). The flower is summarised by a floral formula and a floral diagram.

Floral formula symbols: Br (bracteate); K (calyx); C (corolla); P (perianth); A (androecium); G (gynoecium); G with a line above the letter = inferior ovary, line below = superior ovary; ♂ male; ♀ female; ⚥ bisexual; ⊕ actinomorphic; % zygomorphic. Fusion is shown by enclosing the number in brackets, and adhesion by an arc drawn above the symbols of the joined parts.

A floral diagram shows the number of parts, their arrangement and relation to one another. The mother axis is shown as a dot on top of the diagram; calyx, corolla, androecium and gynoecium are drawn in successive whorls, calyx outermost and gynoecium in the centre.

Family Solanaceae (potato family): a large family found in tropics, subtropics and even temperate zones.

• Vegetative: usually herbs or shrubs, seldom small trees. The stem is mostly soft (seldom woody), above ground, upright, round in section and branched, may be solid or hollow and hairy or smooth; underground stem in potato (*Solanum tuberosum*). Leaves alternate, simple (rarely pinnately compound), exstipulate, with reticulate venation.
• Floral: inflorescence solitary, axillary or cymose (*Solanum*). Flower bisexual, actinomorphic. Calyx: five sepals, united (gamosepalous), persistent, valvate. Corolla: five petals, united, valvate. Androecium: five stamens, epipetalous. Gynoecium: bicarpellary, obliquely placed, syncarpous; ovary superior, bilocular, placenta swollen with many ovules, axile. Fruit: berry or capsule. Seeds: many, endospermous.
• Floral formula: ⊕ ⚥ K(5) C(5) A5 G(2), with an arc joining C and A (epipetalous) and a line under G (superior ovary).
• Economic importance: food (tomato, brinjal, potato), spice (chilli), medicine (belladonna, ashwagandha), fumigatory (tobacco), ornamentals (petunia).

Worked example

Write the floral formula of Solanaceae and explain what each part of it tells you. (3 marks)

Try it first, then show the solutionSolution

1. Floral formula: ⊕ ⚥ K(5) C(5) A5 G(2), with C and A joined by an arc and a line under G. (1)
2. ⊕ actinomorphic; ⚥ bisexual; K(5) five united sepals; C(5) five united petals. (1)
3. A5 five stamens, epipetalous (arc to C); G(2) bicarpellary syncarpous, superior ovary (line below). (1)

Answer: ⊕ ⚥ K(5) C(5) A5 G(2): actinomorphic, bisexual, gamosepalous, gamopetalous, epipetalous stamens, bicarpellary syncarpous superior ovary.

Morphology of Flowering Plants in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Floral Parts, Aestivation and Placentation
• Modifications of Root, Stem and Leaf

Morphology of Flowering Plants: key facts

Floral formula of Solanaceae

$\oplus \text{bisexual}{K}_{(5)}{C}_{(5)}{A}_5{\underline{G}}_{(2)}$

Arc joining C and A for epipetalous stamens; line under G for superior ovary.

Regions of the root tip

$\text{root cap}\to \text{meristematic}\to \text{elongation}\to \text{maturation (root hairs)}$

From the apex upwards.

Position of ovary

$\text{hypogynous (superior)};\text{perigynous (half-inferior)};\text{epigynous (inferior)}$

Mustard; rose/plum/peach; guava/cucumber.

Aestivation types

$\text{valvate},\text{twisted},\text{imbricate},\text{vexillary}$

Calotropis; china rose; Cassia; pea.

Placentation types

$\text{marginal},\text{axile},\text{parietal},\text{free central},\text{basal}$

Pea; china rose; mustard; Dianthus; sunflower.

Pericarp layers

$\text{epicarp}+\text{mesocarp}+\text{endocarp}$

Mango: edible mesocarp; coconut: fibrous mesocarp.

Morphology of Flowering Plants: diagrams to practise

Practise each one on paper: draw it from the checklist, then tick off every label.

How the school exam asks Morphology of Flowering Plants

The question patterns to expect, and the method that works for each.

Tricks to remember Morphology of Flowering Plants

Short memory aids. Say each one aloud once, then use it on a question the same day.

• Cap–Divide–Stretch–Hair

  Root tip regions from the apex: root cap, meristematic, elongation, maturation (root hairs).

  Use it when: Regions of the root.

• Hypo-high, Peri-same, Epi-below

  In hypogynous flowers the ovary is highest (superior); perigynous at the same level (half-inferior); epigynous below the other parts (inferior).

  Use it when: Ovary position questions.

• V-T-I-V aestivation

  Valvate (Calotropis), Twisted (china rose), Imbricate (Cassia), Vexillary (pea).

  Use it when: Aestivation examples.

• MAP-FB placentation

  Marginal (pea), Axile (china rose), Parietal (mustard), Free central (Dianthus), Basal (sunflower).

  Use it when: Placentation examples.

• Solanaceae 5-5-5-2

  K(5) C(5) A5 G(2): five united sepals, five united petals, five epipetalous stamens, two fused carpels.

  Use it when: Floral formula.

Morphology of Flowering Plants: exam-level solved questions

Ordered from exam level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section E style)

Read the situation, then answer every part. In a school exam set on the board pattern this is a 4-mark question split into 1 + 1 + 2 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Morphology of Flowering Plants

The slips examiners see most often, and what to write instead.

• ✗Mistake: Writing the root cap as a growth region

  Students list it as where cells divide.

  ✓Do this: The root cap protects the tip; cell division happens in the meristematic region just behind it.

  Usually costs: ½-1 mark.

• ✗Mistake: Treating leaflets as leaves

  Both look alike.

  ✓Do this: Leaflets have no axillary bud; the whole compound leaf has one in its petiole's axil.

  Usually costs: 1 mark.

• ✗Mistake: Confusing actinomorphic and zygomorphic

  Symmetry terms are mixed.

  ✓Do this: Actinomorphic: any radial plane (mustard); zygomorphic: only one plane (pea).

  Usually costs: ½ mark.

• ✗Mistake: Wrong line under/over G in the floral formula

  The convention is forgotten.

  ✓Do this: Line below G = superior ovary; line above G = inferior ovary.

  Usually costs: ½ mark.

• ✗Mistake: Giving the wrong pericarp layer as edible in mango

  Epicarp is assumed edible.

  ✓Do this: The edible part is the fleshy mesocarp; the stone is the endocarp.

  Usually costs: ½ mark.

• ✗Mistake: Including Fabaceae or Liliaceae when asked about families

  Older guides include them.

  ✓Do this: Only Solanaceae is in the 2026-27 syllabus.

  Usually costs: Time and marks for irrelevant content.

NCERT exercise guide: Morphology of Flowering Plants

What each exercise in the NCERT chapter tests, how to approach it, and a question of the same kind solved step by step. Questions here are written in our own words.

Practice questions on Morphology of Flowering Plants

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · MCQExam level

   Which of the following has perigynous flowers?
   (a) mustard (b) guava (c) rose (d) cucumber

   Hint

   Half-inferior ovary.

   Answer

   (c) rose

2. Q2 · 1 mark · MCQExam level

   The edible part of mango is the:
   (a) epicarp (b) mesocarp (c) endocarp (d) seed

   Hint

   Middle layer.

   Answer

   (b) mesocarp

3. Q3 · 2 marks · Very short answerExam level

   What are monoadelphous and diadelphous stamens? Give one example each. (2 marks)

   Hint

   One or two bundles.

   Answer

   Monoadelphous: stamens united into one bundle, e.g. china rose (1). Diadelphous: two bundles, e.g. pea (1).

4. Q4 · 2 marks · Very short answerHarder exam level

   Name the type of venation in (a) banana leaf (b) mango leaf. To which class does each plant belong? (2 marks)

   Hint

   Monocot vs dicot.

   Answer

   (a) Parallel; monocot (1). (b) Reticulate; dicot (1).

5. Q5 · 2 marks · Very short answerHarder exam level

   Explain how a long, thin, flexible petiole helps a leaf. (2 marks)

   Hint

   Wind.

   Answer

   It lets the blade flutter in the wind (1), which cools the leaf and brings fresh air to its surface (1).

6. Q6 · 2 marks · Very short answerHarder exam level

   Suppose you cut a lemon transversely and see seeds arranged around a central axis in several chambers. Name the placentation and give two other plants with it. (2 marks)

   Hint

   Multilocular ovary.

   Answer

   Axile placentation (1); china rose and tomato (1).

7. Q7 · 3 marks · Short answerHarder exam level

   List the four whorls of a typical flower and state which are essential and which are accessory, with one function of each type. (3 marks)

   Hint

   K, C, A, G.

   Answer

   Calyx, corolla (accessory), androecium, gynoecium (essential/reproductive) (1). Accessory whorls protect the bud (calyx) and attract pollinators (corolla) (1). Androecium produces pollen; gynoecium bears ovules and becomes the fruit (1).

8. Q8 · 2 marks · Very short answerHarder exam level

   What is parthenocarpy? Why are parthenocarpic fruits seedless? (2 marks)

   Hint

   No fertilisation.

   Answer

   Formation of fruit without fertilisation of the ovary (1); since ovules are not fertilised, they do not become seeds (1).

9. Q9 · 3 marks · Short answerHarder exam level

   Draw (in words) and label the floral diagram of a Solanaceae flower. (3 marks)

   Hint

   Concentric whorls, mother axis on top.

   Answer

   A dot (mother axis) above; outer whorl of five fused sepals (valvate); next whorl of five fused petals alternating with sepals (valvate) (1); five stamens attached to petals (epipetalous) (1); in the centre a two-chambered, obliquely placed ovary with swollen axile placentae bearing many ovules (1).

10. Q10 · 3 marks · Short answerHOTS / competency

    Suppose a botanist finds a flower whose ovary lies below the attachment of sepals, petals and stamens, and whose thalamus wall is fused with the ovary. Name the condition, the ovary position, and give two examples. Why might such ovaries be better protected? (3 marks)

    Hint

    Thalamus grows around the ovary.

    Answer

    Epigynous; inferior ovary (1). Examples: guava, cucumber (or ray florets of sunflower) (1). The ovary is enclosed by the fused thalamus, giving extra protection to the ovules (1).

11. Q11 · 5 marks · Long answerHOTS / competency

    (a) Explain why a flower is regarded as a modified shoot. (b) Compare racemose and cymose inflorescences, with reference to the age of flowers. (c) Describe the regions of a root tip and their functions. (5 marks)

    Hint

    Meristem and nodes.

    Answer

    (a) Shoot apical meristem becomes floral meristem; internodes do not elongate; floral appendages arise at successive nodes in place of leaves (1½). (b) Racemose: unlimited axis, acropetal (oldest at base); cymose: limited axis ending in a flower, basipetal (oldest at tip) (1½). (c) Root cap protects the tip; meristematic region divides; elongation region increases length; maturation region differentiates and bears root hairs for absorption (2).

12. Q12 · 1 mark · Assertion-reasonHOTS / competency

    Assertion (A): Coconut is a drupe.
    Reason (R): It develops from a monocarpellary superior ovary and is one-seeded, with a fibrous mesocarp.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.

    Hint

    Definition of drupe.

    Answer

    (a)

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.What is an adventitious root? Give an example.Show answer

   A root arising from any part other than the radicle, e.g. in grass, Monstera, banyan.

2. 2.What are stipules?Show answer

   Small leaf-like lateral outgrowths at the leaf base.

3. 3.Name a plant with whorled phyllotaxy.Show answer

   Alstonia.

4. 4.What is acropetal succession?Show answer

   Arrangement with older flowers at the base and younger flowers towards the tip (racemose).

5. 5.Give an example of a zygomorphic flower.Show answer

   Pea, gulmohur, bean or Cassia.

6. 6.What is a staminode?Show answer

   A sterile stamen.

7. 7.What is parthenocarpic fruit?Show answer

   A fruit formed without fertilisation of the ovary.

8. 8.Name the shield-shaped cotyledon of maize.Show answer

   Scutellum.

9. 9.What is the aleurone layer?Show answer

   The protein-rich outer layer of the endosperm in a monocot seed such as maize.

10. 10.Give two medicinal plants of Solanaceae.Show answer

    Belladonna and ashwagandha.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Can you draw and label the regions of a root tip?
• ☐Can you distinguish reticulate and parallel venation with examples?
• ☐Can you tell pinnate from palmate compound leaves?
• ☐Can you give the three types of phyllotaxy with examples?
• ☐Can you draw hypogynous, perigynous and epigynous flowers?
• ☐Can you name four aestivation and five placentation types with examples?
• ☐Can you label a dicot seed and a maize seed?
• ☐Can you write the semi-technical description and floral formula of Solanaceae?

Morphology of Flowering Plants: frequently asked questions