આ MCQ મોડ્યુલ આના પર આધારિત છે: NCERT Exercises and Solutions: Morphology of Flowering Plants
NCERT Exercises and Solutions: Morphology of Flowering Plants
આ મૂલ્યાંકન આના પર આધારિત હશે: NCERT Exercises and Solutions: Morphology of Flowering Plants
મૂલ્યાંકન બનાવવામાં તેમની સામગ્રી સામેલ કરવા ચિત્રો, PDF અથવા Word દસ્તાવેજ અપલોડ કરો.
NCERT Exercises and Solutions: Morphology of Flowering Plants
Chapter 5 Summary
Angiosperms exhibit enormous variation in shape, size, structure, and mode of nutrition. The body has a clear differentiation into root and shoot. The root system may be tap (mustard, dicots), fibrous (wheat, monocots), or adventitious (banyan). Roots and stems show modifications for storage (radish, carrot, ginger, potato), support (banyan prop, maize stilt), respiration (Rhizophora pneumatophores), climbing (cucumber tendrils), and defence (citrus thorns).
Leaves possess a base, petiole, and lamina; leaves are simple or compound (pinnate or palmate); show reticulate (dicots) or parallel (monocots) venation; phyllotaxy is alternate, opposite, or whorled.
The flower is the reproductive shoot. Inflorescence is racemose (acropetal) or cymose (basipetal). Flowers may be actinomorphic, zygomorphic, or asymmetric; trimerous/tetramerous/pentamerous. Position of ovary on thalamus gives hypogynous, perigynous, epigynous flowers. Aestivation can be valvate, twisted, imbricate, vexillary. Placentation can be marginal, axile, parietal, free central, or basal.
Fruit is a ripened ovary; true (mango), false (apple), simple, aggregate, multiple. Pericarp may have epicarp/mesocarp/endocarp. Seeds are dicot (two cotyledons; bean) or monocot (one cotyledon = scutellum; maize, with aleurone layer, coleoptile, coleorhiza). The floral formula compactly summarises symmetry, sex, calyx, corolla/perianth, androecium, gynoecium and ovary position; major families: Fabaceae, Solanaceae, Liliaceae.
Key Terms
Pulvinus, Vexillum, Caryopsis, Sorosis, Hypanthium
NCERT Exercises
Q1. What is meant by modification of root? What type of modification of root is found in the (a) Banyan tree (b) Turnip (c) Mangrove trees?
(a) Banyan tree: Prop roots — adventitious roots that grow downward from horizontal aerial branches and act as pillars for mechanical support of the heavy crown.
(b) Turnip: Napiform tap root — primary root becomes greatly swollen at the upper part (almost spherical), tapers abruptly below; stores food.
(c) Mangrove trees (Rhizophora): Pneumatophores — many roots grow vertically upward (negatively geotropic) above the marshy soil, with lenticels for gaseous exchange in oxygen-poor mud.
Q2. Justify the following statements on the basis of external features: (a) Underground parts of a plant are not always roots (b) Flower is a modified shoot.
- Many underground parts are stems: potato (tuber with eyes/buds), ginger/turmeric (rhizome with nodes/internodes), onion (bulb with reduced stem disc), colocasia (corm).
- Stems show nodes, internodes, scale leaves, and axillary buds — features absent in roots.
- Roots never bear buds in regular pattern.
- The shoot apical meristem changes to floral meristem when ready to flower.
- Internodes do not elongate; thalamus represents the condensed axis.
- Sepals, petals, stamens, and carpels are modified leaves arranged in whorls (Goethe's foliar theory; supported by ABC genetic model).
- Bracts, pedicels are direct stem features; calyx is leaf-like in many flowers.
Q3. How is a pinnately compound leaf different from a palmately compound leaf?
Palmately compound: Leaflets attached at a common point (tip of the petiole), like fingers from a palm. Examples: silk cotton, Trifolium. Subtypes: unifoliate, bifoliate, trifoliate, quadrifoliate, multifoliate.
Both are compound leaves (lamina divided up to midrib forming separate leaflets) but differ in attachment of leaflets — along an axis (pinnate) vs at a single point (palmate).
Q4. Explain with suitable examples the different types of phyllotaxy.
- Alternate: Single leaf at each node, with successive leaves on opposite sides. e.g., china rose, mustard, sunflower.
- Opposite: Two leaves at each node, opposite to each other. Two sub-types — opposite decussate (successive pairs at right angles, e.g., Calotropis) and opposite superposed (all pairs in same plane, e.g., guava).
- Whorled: More than two leaves at each node, arranged in a whorl. e.g., Alstonia, Nerium.
Q5. Define the following terms: (a) Aestivation (b) Placentation (c) Actinomorphic (d) Zygomorphic (e) Superior ovary (f) Perigynous flower (g) Epipetalous stamen.
(b) Placentation: Arrangement of ovules within the ovary (marginal, axile, parietal, free central, basal).
(c) Actinomorphic: A flower divisible into two equal radial halves through any vertical plane — radial symmetry. e.g., mustard, datura.
(d) Zygomorphic: A flower divisible into two equal halves only by a single vertical plane — bilateral symmetry. e.g., pea, Cassia.
(e) Superior ovary: Ovary attached above the level of attachment of other floral parts (sepals, petals, stamens). Found in hypogynous flowers (mustard, china rose, brinjal).
(f) Perigynous flower: Thalamus is cup-shaped; gynoecium in centre, other parts arise from the rim — at the same level as middle of ovary. Ovary is half-inferior. e.g., rose, plum, peach.
(g) Epipetalous stamen: Stamens that are attached to (united with) the petals. e.g., brinjal, Datura, Solanaceae generally.
Q6. Differentiate between (a) Racemose and Cymose inflorescence (b) Fibrous root and Adventitious root (c) Apocarpous and Syncarpous ovary.
| Feature | Racemose | Cymose |
|---|---|---|
| Main axis | Continues to grow (indeterminate) | Terminates in a flower (determinate) |
| Flower order | Acropetal (older below) | Basipetal (older above) |
| Example | Radish, mustard | Jasmine, Hamelia |
| Feature | Fibrous | Adventitious |
|---|---|---|
| Origin | Base of stem (replaces primary root) | Any non-radicle part |
| Found in | Monocots (wheat, grass) | Monocots & dicots; modifications |
| Example | Wheat seedling | Banyan prop, money plant |
| Feature | Apocarpous | Syncarpous |
|---|---|---|
| Carpels | Free (separate) | Fused |
| Examples | Lotus, rose | Mustard, tomato, papaya |
Q7. Draw the labelled diagrams of the following: (i) Gram seed (ii) V.S. of maize seed.
V.S. of maize seed (monocot): Outer covering = pericarp + testa fused. Bulky endosperm with proteinous aleurone layer just inside the covering. Embryo on one side: scutellum (single shield-shaped cotyledon), embryonal axis with plumule and radicle, both enclosed in protective sheaths — coleoptile (over plumule) and coleorhiza (over radicle).
[See diagrams in Part 3 of this chapter for full SVG illustrations.]
Q8. Describe modifications of stem with suitable examples.
- Rhizome: ginger, turmeric — horizontal, with nodes/internodes, scale leaves.
- Tuber: potato — swollen tip of underground branch; eyes are buds.
- Bulb: onion, garlic — disc-like reduced stem with fleshy scale leaves.
- Corm: Colocasia, Crocus — vertical underground stem.
- Runner: grass, mint — creeping stem rooting at nodes.
- Stolon: mint, jasmine — slender lateral branch arching down.
- Offset: Pistia, Eichhornia — short thicker runner in aquatic plants.
- Sucker: banana, Chrysanthemum — arises from underground stem, grows obliquely upward.
- Tendril: Cucurbita — thin coiling for climbing.
- Thorn: Bougainvillea, Citrus — defence (modified axillary bud).
- Phylloclade: Opuntia — flattened green stem, photosynthetic.
- Cladode: Asparagus — green stem of one or two internodes.
Q9. Take one flower each of the families Fabaceae and Solanaceae and write its semi-technical description. Also draw their floral diagram after studying them.
Habit: Annual herb, climbing by leaf tendrils. Root: Tap with nodules. Stem: Weak, climbing. Leaves: Pinnately compound; terminal leaflets modified to tendrils; stipules large and leafy. Inflorescence: Axillary raceme. Flower: Bisexual, zygomorphic. Calyx: K(5), gamosepalous. Corolla: C1+2+(2), papilionaceous, vexillary aestivation. Androecium: A(9)+1, diadelphous. Gynoecium: G1, monocarpellary, superior. Fruit: Legume.
Floral formula: % ⚥ K(5) C1+2+(2) A(9)+1 G1
Solanaceae — Datura (Datura stramonium):
Habit: Erect annual herb. Stem: Cylindrical, hollow. Leaves: Alternate, simple, lobed, exstipulate. Inflorescence: Solitary axillary cyme. Flower: Bisexual, actinomorphic. Calyx: K(5), gamosepalous, persistent, valvate. Corolla: C(5), gamopetalous, funnel-shaped, valvate. Androecium: A5, epipetalous. Gynoecium: G(2), bicarpellary, syncarpous, ovary superior, bilocular, swollen axile placentation. Fruit: Capsule.
Floral formula: ⊕ ⚥ K(5) C(5) A5 G(2)
[Floral diagrams: See Fig 5.13 and 5.14 in Part 4 of this chapter.]
Q10. Describe the various types of placentations found in flowering plants.
- Marginal: Placenta forms a ridge along the ventral suture; ovules borne in two rows. Unilocular. e.g., pea (Fabaceae).
- Axile: Ovary multilocular; placenta is axial; ovules attached to central axis. e.g., china rose, tomato, lemon.
- Parietal: Ovules develop on the inner wall of the unilocular ovary or on peripheral placentae. e.g., mustard, Argemone.
- Free central: Ovules are borne on a central axis, with no septa dividing the ovary. e.g., Dianthus, Primrose.
- Basal: Placenta develops at the base of ovary; only a single ovule attached. e.g., sunflower, marigold.
Q11. What is a flower? Describe the parts of a typical angiosperm flower.
Parts of a typical flower (4 whorls on thalamus):
- Calyx (sepals): Outermost, generally green and leaf-like; protects the bud. May be free (polysepalous) or united (gamosepalous).
- Corolla (petals): Inner to calyx; brightly coloured to attract pollinators. Free (polypetalous) or united (gamopetalous). Aestivation may be valvate, twisted, imbricate, or vexillary.
- Androecium (stamens): Each stamen has a filament + anther (bilobed, bearing pollen sacs). Sterile = staminode. Stamens may fuse to form bundles (mono-, di-, polyadelphous) or attach to petals (epipetalous).
- Gynoecium (carpels): Female part. Each carpel has a stigma (pollen-receiving), style (connecting), and ovary (containing ovules on placenta). Carpels may be free (apocarpous) or fused (syncarpous).
Q12. How do the various leaf modifications help plants?
- Tendrils (climbing): Leaves modified for support; pea (terminal leaflets), Smilax. Help weak-stemmed plants climb to reach light.
- Spines (defence + reduced transpiration): Leaves modified into hard pointed structures; cactus (Opuntia). Protect against herbivores; reduce surface area to conserve water.
- Storage: Fleshy leaves of onion/garlic store food and water for the plant.
- Phyllode (photosynthesis substitute): Petiole flattens and turns green; Australian acacia. Used in dry climates where leaves would lose too much water.
- Pitcher (insect trapping): Highly modified leaf in pitcher plant traps insects to supplement nitrogen in nitrogen-poor soils.
- Bladder (Utricularia): Modified leaf-bladder with trap-doors to catch micro-organisms.
- Floral leaves (bracts): Brightly coloured leaves attract pollinators in Bougainvillea, poinsettia.
Q13. Define the term inflorescence. Explain the basis for the different types of inflorescence in flowering plants.
Basis of classification: Whether the apex of the main axis is converted into a flower or continues to grow.
- Racemose: Main axis continues to grow (indeterminate); flowers borne laterally in acropetal succession (older flowers below, younger above). e.g., radish, mustard, larkspur. Sub-types: simple raceme, spike, catkin, spadix, corymb, umbel, head/capitulum.
- Cymose: Main axis ends in a flower (determinate); growth limited; younger flowers below the older one (basipetal). e.g., Jasminum, Hamelia. Sub-types: uniparous (monochasial), biparous (dichasial), multiparous (polychasial).
Q14. Write the floral formula of an actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens and two united carpels with superior ovary and axile placentation.
- Actinomorphic = ⊕
- Bisexual = ⚥
- Hypogynous = ovary superior, written as G with line above (or simply listed last with no underline)
- 5 sepals united = K(5)
- 5 petals free = C5
- 5 stamens free = A5
- 2 carpels united, superior ovary, axile placentation = G(2)
This matches family Solanaceae (e.g., petunia, datura).
Q15. Describe the arrangement of floral members in relation to their insertion on thalamus.
- Hypogynous flower: Gynoecium occupies the highest position; calyx, corolla, and androecium are inserted below it. Ovary superior. e.g., mustard, china rose, brinjal.
- Perigynous flower: Thalamus is cup-shaped; gynoecium in the centre; other parts inserted at the rim, at the same level as the middle of the ovary. Ovary half-inferior. e.g., plum, rose, peach.
- Epigynous flower: Margin of thalamus grows upward enclosing the ovary completely; calyx, corolla, and androecium attach above the ovary. Ovary inferior. e.g., guava, cucumber, ray florets of sunflower.
Setup: Take a walk in your school garden / nearby park. Pick five different plants.
Sample 1: Hibiscus (china rose) — Tap root; reticulate venation; actinomorphic flower; superior ovary → Dicot (Malvaceae).
Sample 2: Onion plant in flower — Bulb (modified stem); parallel venation; actinomorphic flower with perianth → Monocot (Liliaceae).
Sample 3: Tomato plant — Tap root; reticulate venation; actinomorphic flower; superior bilocular ovary → Dicot (Solanaceae).
Sample 4: Pea plant — Tap root with nodules; pinnately compound leaves with leaflet-tendrils; zygomorphic vexillary flower → Dicot (Fabaceae).
Sample 5: Grass — Fibrous root; parallel venation; reduced flowers in spikelets → Monocot (Poaceae).
Interactive: Quick Revision Quiz
Test yourself — pick the right answer and reveal:
Which of the following is a false fruit?
In Liliaceae, the perianth has how many tepals?
Competency-Based Questions
Q1. The fleshy edible part of mango is: L1 Remember
Q2. The 'eyes' of a potato are actually: L2 Understand
Q3. Match the family with its key floral feature: L3 Apply
Solanaceae: 5 epipetalous stamens; bicarpellary syncarpous ovary
Liliaceae: 6 tepals (3+3); 6 stamens; tricarpellary; parallel venation in leaves
Q4. Analyse: A plant has tap root with nodules, pinnately compound leaves, zygomorphic flowers, vexillary aestivation, fruit = pod. Identify and explain ecological significance. L4 Analyse
Ecological significance:
- Root nodules contain Rhizobium → fix atmospheric N₂ → enrich soil with usable nitrogen
- Used as cover/rotation crops to restore soil fertility (no synthetic fertilisers)
- Seeds rich in protein → vital food source in vegetarian diets
- Pod fruit dispersal mechanism allows wide colonisation
Q5. Create: Design a poster summarising the morphological features that distinguish dicots from monocots. L6 Create
| Feature | Dicot | Monocot |
|---|---|---|
| Cotyledons | Two | One |
| Root | Tap root | Fibrous root |
| Venation | Reticulate | Parallel |
| Flower | Tetra/Pentamerous (4/5) | Trimerous (3 or multiple of 3) |
| Vascular bundles in stem | In a ring; with cambium (open) | Scattered; without cambium (closed) |
| Examples | Mango, mustard, hibiscus | Wheat, lily, banana |
Assertion–Reason Questions
Choose: (A) Both true, R explains A. (B) Both true, R doesn't explain A. (C) A true, R false. (D) A false, R true.
A: Coconut is a drupe.
R: The pericarp of coconut is differentiated into thin epicarp, fibrous mesocarp, and stony endocarp.
A: Maize seed is monocotyledonous.
R: It contains coleoptile and coleorhiza.
A: The flowers of pea are zygomorphic.
R: The petals show vexillary aestivation with one large standard, two lateral wings, and two innermost keel petals.