NCERT Solutions for Class 11 Biology Chapter 5: Morphology of Flowering Plants (NCERT 2026–27)
These Class 11 Biology Chapter 5 solutions cover Morphology of Flowering Plants from the NCERT textbook (session 2026–27). The chapter studies the external form of angiosperms — the root, stem, leaf, inflorescence, flower, fruit and seed — along with the standard technical terms used to describe each part, the floral formula and diagram, and the semi-technical description of a family (Solanaceae). Below you will find every end-of-chapter Exercise reproduced verbatim and answered in clear, exam-ready prose, plus extra practice, MCQs, Assertion–Reason questions, common mistakes, exam tips and FAQs.
Although angiosperms show enormous diversity in external form, they are all built on a common plan: a root system below the ground and a shoot system (stem, leaves, flowers, fruits) above it. The chapter first describes roots (tap, fibrous and adventitious) and the regions of a root tip, then the stem with its nodes, internodes and buds, and the leaf with its three parts, venation, simple/compound forms and phyllotaxy. It then moves to the inflorescence (racemose vs cymose), the flower (its four whorls, symmetry, position of the ovary, aestivation and placentation), the fruit and the seed (dicot and monocot). Finally it teaches the semi-technical description of a flowering plant using a floral diagram and floral formula, illustrated with the family Solanaceae. Mastering the technical vocabulary here is essential, because it is the language used throughout plant biology.
Key Concepts & Definitions
Tap root system: a system in which the primary root (from the radicle) and its branches dominate, e.g. in dicots like mustard.
Fibrous root system: many similar roots arising from the base of the stem, replacing a short-lived primary root, e.g. in monocots like wheat.
Adventitious roots: roots that arise from any part of the plant other than the radicle, e.g. in grass, Monstera and the banyan tree.
Phyllotaxy: the pattern of arrangement of leaves on a stem or branch — alternate, opposite or whorled.
Venation: the arrangement of veins and veinlets in the lamina — reticulate (network, typical of dicots) or parallel (typical of monocots).
Inflorescence: the arrangement of flowers on the floral axis — racemose (main axis grows, flowers acropetal) or cymose (main axis ends in a flower, flowers basipetal).
Aestivation: the mode of arrangement of sepals or petals in the floral bud — valvate, twisted, imbricate or vexillary.
Placentation: the arrangement of ovules within the ovary — marginal, axile, parietal, basal, central and free central.
Floral formula & floral diagram: a symbolic and a pictorial summary, respectively, of the number, arrangement, fusion and relationship of the floral parts.
NCERT Exercises — Class 11 Biology Chapter 5 Solutions
All questions below are reproduced verbatim from the NCERT textbook (Reprint 2026–27). Answers are original and written in CBSE exam-ready style.
1. How is a pinnately compound leaf different from a palmately compound leaf?
ANSWERIn a pinnately compound leaf, a number of leaflets are arranged on both sides of a common central axis called the rachis, which represents the midrib of the leaf, e.g. neem. The leaflets are borne along the length of this axis like the feathers of a quill.In a palmately compound leaf, all the leaflets are attached to a single common point, i.e. at the tip of the petiole, and spread out like the fingers of a palm, e.g. silk cotton. Thus the key difference is the point of attachment: along a rachis (pinnate) versus at one common tip of the petiole (palmate).
2. Explain with suitable examples the different types of phyllotaxy.
ANSWERPhyllotaxy is the pattern of arrangement of leaves on the stem or branch. It is of three main types:(i) Alternate phyllotaxy: a single leaf arises at each node in an alternate manner, e.g. china rose, mustard and sunflower.(ii) Opposite phyllotaxy: a pair of leaves arises at each node and the two lie opposite to each other, e.g. Calotropis and guava.(iii) Whorled phyllotaxy: more than two leaves arise at a node and form a whorl, e.g. Alstonia.
ANSWER(a) Aestivation: the mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl (e.g. valvate, twisted, imbricate, vexillary).(b) Placentation: the arrangement of ovules within the ovary (e.g. marginal, axile, parietal, basal, central, free central).(c) Actinomorphic: a flower that can be divided into two equal radial halves by any radial plane passing through the centre, i.e. it has radial symmetry, e.g. mustard, datura, chilli.(d) Zygomorphic: a flower that can be divided into two similar halves only in one particular vertical plane, i.e. it has bilateral symmetry, e.g. pea, gulmohur, bean, Cassia.(e) Superior ovary: an ovary that occupies the highest position on the thalamus while the other floral parts lie below it, as in a hypogynous flower (e.g. mustard, china rose, brinjal).(f) Perigynous flower: a flower in which the gynoecium is in the centre and the other floral parts arise on the rim of the thalamus at almost the same level, so the ovary is half inferior, e.g. plum, rose, peach.(g) Epipetalous stamen: a stamen that is attached to (borne on) the petals of the corolla, e.g. in brinjal.
4. Differentiate between
(a) Racemose and cymose inflorescence (b) Apocarpous and syncarpous ovary
ANSWER(a) Racemose vs Cymose inflorescence:
Racemose
Cymose
The main axis continues to grow and does not end in a flower.
The main axis terminates in a flower and so is limited in growth.
Flowers are borne laterally in an acropetal succession (older flowers at the base, younger towards the apex).
Flowers are borne in a basipetal order (older flower at the tip, younger towards the base).
(b) Apocarpous vs Syncarpous ovary:
Apocarpous
Syncarpous
More than one carpel is present and the carpels are free (unfused).
The carpels are fused together.
Examples: lotus and rose.
Examples: mustard and tomato.
5. Draw the labelled diagram of the following:
(i) gram seed (ii) V.S. of maize seed
ANSWERAs ClearStudy pages do not reproduce textbook images, the structures to be drawn and labelled are described below from the NCERT figures so you can sketch and label them accurately.(i) Gram seed (dicotyledonous, non-endospermic): Draw a bean-shaped seed. Label the seed coat (with its outer testa and inner tegmen), the hilum (scar on the seed coat) and just above it the micropyle (small pore). Inside, show the embryo: two fleshy cotyledons full of reserve food, the embryonal axis, and at its two ends the radicle and the plumule.(ii) V.S. of maize seed (monocotyledonous, endospermic): Draw a longitudinal section showing the outer seed coat fused with the fruit wall (pericarp), a large bulky endosperm bordered by the aleurone layer, and the embryo lying in a groove at one end. Label the single shield-shaped cotyledon, the scutellum, and the short axis with the plumule enclosed in a coleoptile and the radicle enclosed in a coleorhiza.
6. Take one flower of the family Solanaceae and write its semi-technical description. Also draw their floral diagram.
ANSWERTaking Solanum nigrum (makoi), a typical member of the family Solanaceae, the semi-technical description is:Vegetative characters —Habit: mostly herbs, shrubs and rarely small trees. Stem: herbaceous, rarely woody, aerial, erect, cylindrical, branched, solid or hollow, hairy or glabrous (underground stem in potato). Leaves: alternate, simple, rarely pinnately compound, exstipulate, with reticulate venation.Floral characters —Inflorescence: solitary, axillary or cymose. Flower: bisexual, actinomorphic. Calyx: sepals five, united (gamosepalous), persistent, valvate aestivation. Corolla: petals five, united (gamopetalous), valvate aestivation. Androecium: stamens five, epipetalous. Gynoecium: bicarpellary, syncarpous; ovary superior, bilocular with a swollen axile placenta bearing many ovules. Fruit: a berry or capsule. Seeds: many, endospermous.Floral formula: Br ⊕ ♂♀ K(5) C(5) A5 G(2) (bracteate, actinomorphic, bisexual; calyx 5 united; corolla 5 united; androecium 5 epipetalous; gynoecium bicarpellary syncarpous, superior).Floral diagram: Draw concentric whorls with a dot (mother axis) at the top, then five fused sepals (outermost), five fused petals, five stamens attached to the petals (epipetalous), and at the centre the superior bilocular ovary with axile placentation showing two chambers and ovules.
7. Describe the various types of placentations found in flowering plants.
ANSWERPlacentation is the arrangement of ovules within the ovary. The main types are:Marginal: the placenta forms a ridge along the ventral suture of a single-chambered ovary and the ovules are borne on it in two rows, e.g. pea.Axile: the placenta is axial and the ovules are attached to it in a multilocular (chambered) ovary, e.g. china rose, tomato and lemon.Parietal: the ovules develop on the inner wall or peripheral part of the ovary; the ovary is one-chambered but may become two-chambered by a false septum, e.g. mustard and Argemone.Free central: the ovules are borne on a central axis and septa are absent, e.g. Dianthus and primrose.Basal: the placenta develops at the base of the ovary and a single ovule is attached to it, e.g. sunflower and marigold.
8. What is a flower? Describe the parts of a typical angiosperm flower.
ANSWERA flower is a modified shoot in which the shoot apical meristem changes into a floral meristem; it is the reproductive unit of angiosperms, meant for sexual reproduction. A typical flower has four whorls arranged on the swollen end of the stalk (pedicel), called the thalamus or receptacle. The four whorls are:(i) Calyx: the outermost whorl, made of sepals. Sepals are usually green and leaf-like and protect the flower in the bud stage. They may be gamosepalous (united) or polysepalous (free).(ii) Corolla: made of petals, usually brightly coloured to attract insects for pollination. It may be gamopetalous (united) or polypetalous (free) and may be tubular, bell-, funnel- or wheel-shaped.(iii) Androecium: the male whorl, made of stamens; each stamen has a filament and a bilobed anther whose pollen-sacs produce pollen grains. A sterile stamen is a staminode.(iv) Gynoecium: the female whorl, made of one or more carpels; each carpel has a stigma, style and ovary, and the ovary bears ovules on the placenta. Calyx and corolla are accessory organs, while androecium and gynoecium are the reproductive organs.
9. Define the term inflorescence. Explain the basis for the different types inflorescence in flowering plants.
ANSWERInflorescence is the arrangement of flowers on the floral axis.The basis for classifying inflorescences is the behaviour (fate) of the main axis — that is, whether the apex of the main axis gets converted into a flower or continues to grow vegetatively. On this basis there are two major types:(i) Racemose: the main axis continues to grow indefinitely and does not end in a flower; the flowers are borne laterally in an acropetal succession (older flowers below, younger above).(ii) Cymose: the main axis terminates in a flower and so has limited growth; the flowers are borne in a basipetal order (older flower at the tip, younger ones below).
10. Describe the arrangement of floral members in relation to their insertion on thalamus.
ANSWERBased on the position of the calyx, corolla and androecium with respect to the ovary on the thalamus, flowers are of three types:(i) Hypogynous: the gynoecium occupies the highest position and the other floral parts are situated below it. The ovary is said to be superior, e.g. mustard, china rose and brinjal.(ii) Perigynous: the gynoecium is in the centre and the other parts are borne on the rim of the thalamus at almost the same level as the ovary. The ovary is said to be half inferior, e.g. plum, rose and peach.(iii) Epigynous: the margin of the thalamus grows upward, completely enclosing and fusing with the ovary, so the other floral parts arise above the ovary. The ovary is said to be inferior, e.g. guava, cucumber and the ray florets of sunflower.
Extra Practice Questions
Short Answer Type Questions
Q1. Name the three regions of a root tip in order from the apex.
ANSWERFrom the tip upward: the root cap, then the region of meristematic activity, then the region of elongation, and finally the region of maturation (from which root hairs arise).
Q2. Distinguish between a simple leaf and a compound leaf.
ANSWERIn a simple leaf the lamina is entire, or if incised the incisions do not reach the midrib. In a compound leaf the incisions of the lamina reach the midrib, breaking it into separate leaflets. A bud is present in the axil of the petiole in both, but not in the axil of the leaflets.
Q3. What is a parthenocarpic fruit?
ANSWERA fruit that is formed from the ovary without fertilisation is called a parthenocarpic fruit. Such fruits are generally seedless.
Q4. Differentiate between endospermic and non-endospermic seeds with examples.
ANSWEREndospermic (albuminous) seeds retain the endosperm as a food-storing tissue in the mature seed, e.g. castor and maize. Non-endospermic (exalbuminous) seeds have no endosperm in the mature seed because it is consumed during development, and food is stored in the cotyledons, e.g. bean, gram and pea.
Q5. Name the parts of a drupe such as the mango and state the nature of each.
ANSWERA mango drupe has a thin outer epicarp (skin), a fleshy edible middle mesocarp, and a stony hard inner endocarp enclosing the single seed. It develops from a monocarpellary, superior ovary.
Long Answer Type Questions
Q1. Compare the structure of a dicotyledonous seed with that of a monocotyledonous seed.
ANSWERA dicotyledonous seed (e.g. gram) has a seed coat of two layers, the outer testa and inner tegmen, a hilum and above it a micropyle. Inside lies the embryo with an embryonal axis and two fleshy cotyledons that usually store food; the radicle and plumule lie at the two ends of the axis. Many dicot seeds are non-endospermic, although castor is endospermic. A monocotyledonous seed (e.g. maize) has a membranous seed coat generally fused with the fruit wall, and is usually endospermic with a bulky endosperm bordered by a proteinous aleurone layer. The embryo is small, lies in a groove at one end, and has a single large shield-shaped cotyledon called the scutellum; the plumule is enclosed in a coleoptile and the radicle in a coleorhiza. Thus the major contrasts are the number of cotyledons, the presence and bulk of endosperm, and the protective sheaths around the embryo.
Q2. Explain the different types of aestivation seen in the corolla with examples.
ANSWERAestivation is the mode of arrangement of sepals or petals in a floral bud. Valvate: the members just touch one another at the margins without overlapping, e.g. Calotropis. Twisted: one margin of each member overlaps that of the next in a regular direction, e.g. china rose, lady’s finger and cotton. Imbricate: the margins overlap one another but not in any particular direction, e.g. Cassia and gulmohur. Vexillary (papilionaceous): seen in pea and bean, where the largest petal (standard) overlaps the two lateral petals (wings), which in turn overlap the two smallest anterior petals (keel). Recognising aestivation helps in identifying plant families.
Q3. Describe how the position of the ovary on the thalamus is used to classify flowers, with examples.
ANSWERThe relative position of the calyx, corolla and androecium with respect to the ovary divides flowers into three groups. In a hypogynous flower the gynoecium is highest and the other parts lie below it, giving a superior ovary, e.g. mustard and brinjal. In a perigynous flower the other parts are borne on the rim of a cup-shaped thalamus at the level of the ovary, giving a half-inferior ovary, e.g. rose and plum. In an epigynous flower the thalamus grows up and fuses around the ovary so the other parts arise above it, giving an inferior ovary, e.g. guava, cucumber and the ray florets of sunflower. This terminology is important for describing flowers accurately and for writing floral formulae.
MCQs
1. The fibrous root system is characteristic of:
(a) mustard (b) wheat (c) banyan (d) gram
2. Roots arising from parts of the plant other than the radicle are called:
For each question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.
A-R 1. Assertion: Monocots usually have a fibrous root system.
Reason: In monocots the primary root is short lived and is replaced by many roots arising from the base of the stem.
A-R 2. Assertion: A flower is regarded as a modified shoot.
Reason: In a flower the shoot apical meristem changes into a floral meristem and the condensed axis bears floral appendages instead of leaves.
A-R 3. Assertion: In a racemose inflorescence the flowers open in a basipetal succession.
Reason: In a racemose inflorescence the main axis continues to grow and the flowers are borne laterally.
A-R 4. Assertion: In an epigynous flower the ovary is said to be inferior.
Reason: The margin of the thalamus grows upward, enclosing and fusing with the ovary, so the other floral parts arise above it.
A-R 5. Assertion: In Solanaceae the stamens are epipetalous.
Reason: The five stamens of Solanaceae are attached to the petals of the corolla.
Answer key: 1-(A), 2-(A), 3-(C), 4-(A), 5-(A).
Common Mistakes to Avoid
Watch out for these
Confusing acropetal (racemose, younger flowers at the top) with basipetal (cymose, younger flowers at the base) succession.
Mixing up pinnately compound (leaflets on a rachis, e.g. neem) and palmately compound (leaflets at one point, e.g. silk cotton) leaves.
Reversing ovary position terms — remember hypogynous = superior ovary, epigynous = inferior ovary, perigynous = half inferior.
Swapping axile placentation (multilocular ovary, central placenta) with parietal (one-chambered, ovules on the wall).
Forgetting that the scutellum is the cotyledon of a monocot seed, while coleoptile and coleorhiza are protective sheaths.
Writing the floral formula with wrong fusion symbols — use brackets ( ) to show fused (united) parts.
How to score full marks in this chapter
This chapter is vocabulary-heavy, so define each term precisely and always add the textbook’s example (e.g. mustard for actinomorphic, pea for zygomorphic, neem for pinnate). For “differentiate” questions, answer in a two-column table for clarity. Learn one standard example for every placentation, aestivation and ovary-position type. For the Solanaceae description, memorise the floral formula and practise the floral diagram. When a question asks you to draw, give neat, fully labelled diagrams — labels carry marks.
Frequently Asked Questions
What is Class 11 Biology Chapter 5 about?
Chapter 5, Morphology of Flowering Plants, describes the external structure of angiosperms — the root, stem, leaf, inflorescence, flower, fruit and seed — together with the technical terms (venation, phyllotaxy, aestivation, placentation, ovary position), the floral formula and diagram, and the semi-technical description of the family Solanaceae.
How many exercise questions are there in this chapter?
The NCERT textbook has 10 numbered Exercise questions at the end of Chapter 5. All of them are reproduced verbatim and solved in exam-ready prose on this page.
What is the floral formula of Solanaceae?
For a typical Solanaceae flower it is Br ⊕ ♂♀ K(5) C(5) A5 G(2) — bracteate, actinomorphic, bisexual, with five united sepals, five united petals, five epipetalous stamens, and a bicarpellary syncarpous superior ovary.
Are these Class 11 Biology Chapter 5 solutions free?
Yes. All solutions are free and follow the official NCERT Biology textbook for session 2026–27.
