Frequently Asked Questions

NCERT Solutions Class 11 Biology Chapter 5 - Morphology of Flowering Plants

NCERT Solutions for Class 11 Biology Chapter 5, Morphology of Flowering Plants, explain the external structure and different forms of flowering plants. The chapter covers the structure, functions, and modifications of roots, stems, leaves, flowers, fruits, and seeds, along with important features used to identify plants.

NCERT Solutions for Class 11 Biology Chapter 5 by ALLEN provide clear explanations of important terms such as phyllotaxy, aestivation, and placentation. Students can understand different root and stem modifications, types of leaves and inflorescences, floral structures, and the characteristics of Fabaceae, Solanaceae, and Liliaceae. The solutions also explain floral formulae and floral diagrams, helping students understand the important concepts and examples given in NCERT Class 11 Biology Chapter 5.

1.0Class 11 Biology Chapter 5 Morphology of Flowering Plants: Key Concepts

Class 11 Biology Chapter 5, Morphology of Flowering Plants, explains the external structure, functions, and modifications of different plant parts. The key concepts covered in this chapter include:

The Root: Learn about tap roots, fibrous roots, and adventitious roots, along with root modifications for storage, support, and respiration, such as prop roots, stilt roots, and pneumatophores.
The Stem: Understand the main features of stems and their modifications for storage, support, protection, and photosynthesis, including rhizomes, tubers, tendrils, thorns, and phylloclades.
The Leaf: Study the parts of a leaf, venation, simple and compound leaves, and phyllotaxy, including reticulate and parallel venation.
Inflorescence: Understand the arrangement of flowers on the floral axis and the differences between racemose and cymose inflorescences.
The Flower: Learn about the structure and parts of a flower, including calyx, corolla, androecium, and gynoecium, along with actinomorphic and zygomorphic symmetry and different types of placentation.
Fruit and Seed: Study the basic structure and development of fruits, along with the differences between dicot and monocot seeds.
Important Plant Families: Learn the characteristics, floral features, and floral formulae of Fabaceae, Solanaceae, and Liliaceae.

2.0NCERT Solutions Class 11 Biology Chapter 5 - Morphology of Flowering Plants: Detailed Solutions

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

Ans. A pinnately compound leaf is one in which the leaflets are present on a common axis called rachis, e.g. Neem. A palmately compound leaf is one in which the leaflets are attached at a common point, e.g. Silk cotton.

Pinnately compound leaf	Palmately compound leaf
Leaflets are present on a common axis called rachis.	Leaflets are attached at a common point.
Resembles a featherlike arrangement. Example: Neem	Resembles a palm-like arrangement. Example: Silk cotton

2. Explain with suitable examples the different types of phyllotaxy. Ans. Phyllotaxy is the pattern of arrangement of leaves on the stem or branch. It is usually of three types - alternate, opposite and whorled. (1) In alternate type of phyllotaxy, a single leaf arises at each node in alternate manner, as in china rose, mustard and sunflower plants. (2) In opposite type, a pair of leaves arises at each node and lie opposite to each other as in Calotropis and guava plants. If more than two leaves arise at a node and form a whorl it is called whorled phyllotaxy as in Alstonia.
3. Define the following terms: (a) aestivation (b) placentation (c) actinomorphic (d) zygomorphic (e) superior ovary (f) perigynous flower (g) epipetalous stamen.

Ans.

(a) Aestivation : The mode of arrangement of accessory floral organs (sepals and petals) in relation to one another in floral bud is known as aestivation. The main type of aestivation are valvate, twisted, imbricate, and vexillary. (b) Placentation : The arrangement of ovules within the ovary is known as placentation. The placentation are of different types namely, marginal, axile, parietal, basal, and free central. (c) Actinomorphic : When flower can be divided into equal radial halves in any radial plane passing through the centre, it is said to be actinomorphic, e.g., mustard, Datura etc. (d) Zygomorphic : When a flower can be divided into two similar halves only in one particular vertical plane, it is said to be zygomorphic, e.g., pea, gulmohar, bean, Cassia. (e) Superior ovary : In hypogynous flower, the gynoecium occupies the highest position while the other parts are situated below it. The ovary in such flowers is said to be superior, e.g., mustard, brinjal. (f) Perigynous flower: If gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous. Here ovary is half superior, e.g., peach, plum. (g) Epipetalous stamen : When stamens are attached to the petals, they are called epipetalous stamens e.g., brinjal.

Differentiate between (a) Racemose and cymose inflorescence (b) Fibrous root and adventitious root (c) Apocarpous and syncarpous ovary

Ans.

(a) Differences between racemose and cymose inflorescence are as follows:

Racemose inflorescence	Cymose inflorescence
The main axis continues to grow.	The main axis terminates in a flower.
Growth is unlimited.	Growth is limited.

(iii) The flowers are Flowers are borne in borne in an a basipetal acropetal succession. (iv) The grouping of The grouping of flowers is less flower is more common and common and arrangement of arrangement of flowers in a group flowers in a group is centripetal. Ex. - Jasmine (b) Differences between fibrous and adventitious roots are as follows :

Fibrous root	Adventitious root
It occurs in place of tap root system at the base of main stem.	Roots arise from various parts of the plant other than the radicle.
The roots are thin and fibrous.	The roots can be thin, thick or variously midified.
The root system is underground.	It can be underground or above ground.
Fibrous root system takes part in fixation of plant, absorption of water and mineral salts etc.	It performs several functions like clinging, support, storage, reproduction, fixation, absorption, etc.

(c) Differences between apocarpous and syncarpous ovary are as follows :

Apocarpous ovary	Syncarpous ovary
The flower has several free ovaries.	There is a single ovary.
It is always unilocular.	It can be unilocular or multilocular.
On maturity it forms fruitlet of aggregate type.	On maturity it forms a simple fruit.

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

Labelled diagrams of a gram seed and a vertical section of a maize seed showing their main parts.

6. Take one flower each of the families Fabaceae and Solanaceae and write their semi-technical description. Also draw their floral diagram after studying them. Ans. Family-Fabaceae (e.g., Pisum sativum) Systematic position: Class - Dicotyledoneae Subclass - Polypetalae Series - Calyciflorae Order - Rosales Family - Fabaceae Vegetative characters: Habit: herb. Root: tap, branched, with root nodules. Stem: herbaceous, climbing.

Leaves : pinnately compound, leaf base pulvinate, stipulate, venation reticulate. Floral characters: Inflorescence: racemose. Flower : bisexual, zygomorphic, irregular, hermaphrodite, white or pink, complete, hypogynous to perigynous. Calyx : sepals five, gamosepalous, ascending, imbricate aestivation, campanulate calyx tube. Corolla : petals five, polypetalous, vexillary aestivation, papilionaceous, consisting of a posterior standard or vexillum two lateral wings or alae, two anterior ones forming a keel.

Androecium : 10 stamens in two bundles (diadelphous) of (9) + 1, anthers dithecous (bilobed), basifixed, introrse. Gynoecium : ovary superior, monocarpellary, unilocular with many ovules, marginal placentation, style bent and long, stigma simple and-hairy. Fruit : legume; seeds one to many, nonendospermic. Floral formula : % $\underline{ρ}^{7} K_{(5)} C_{1 + 2 + (2)} A_{(9) + 1} \underline{G}_{1}$

Floral diagram of Pisum sativum showing the arrangement of sepals, petals, stamens, and carpel.

Family-Solanaceae (e.g., Solanum nigrum) Systematic position : Class Subclass Series Order Family Vegetative characters: Habit: herbs Stem : herbaceous, aerial, erect, cylindrical, branched. Leaves: alternate, simple, exstipulate, venation reticulate. Floral characters: Inflorescence: cymose.

Flower : ebracteate, ebracteolate, bisexual, actinomorphic, white, hypogynous. Calyx : sepals five, gamosepalous, persistent, valvate aestivation.

Corolla : petals five, gamopetalous, valvate. aestivation.

Androecium : stamens five, epipetalous, polyandrous, anthers large, bithecous and basifixed.

Gynoecium : bicarpellary, syncarpous, ovary, obliquely placed carpels in the flower, bilocular, axile placentation, placenta swollen with many ovules.

Fruits : berry with persistent calyx. Floral formula :

Floral diagram of Solanum nigrum showing the arrangement of sepals, petals, stamens, and carpel.

Describe the various types of placentations found in flowering plants. Ans. Placenta is a parenchymatous cushion present inside the ovary where ovules are borne. The number, position, arrangement or distribution of placentae inside an ovary is called placentation. The placentation are of different types namely, marginal, axile, parietal, basal and free central. (i) Marginal placentation : The placenta forms a ridge along the ventral suture of the ovary and the ovules are borne on this ridge forming two rows, e.g., pea. (ii) Axile placentation : When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentation is said to be axile, e.g., china rose, tomato and lemon.

(iii) Parietal placentation : The ovules develop on the inner wall of the ovary or on peripheral part. Ovary is one-chambered but it becomes two-chambered due to the formation of the false septum, e.g., mustard and Argemone. (iv) Free central placentation : When the ovules are borne on central axis and septa are absent, as in Dianthus and primrose the placentation is called free central. (v) Basal placentation: The placenta develops at the base of ovary and a single ovule is attached to it, as in sunflower, marigold.

What is a flower? Describe the parts of a typical angiosperm flower. Ans. A flower is a modified shoot in which the shoot apical meristem changes to floral meristem under the influence of internal and external factors. A typical flower consists of four main whorls:

1. Calyx : The calyx is the outermost whorl and consists of sepals. Sepals are generally green and protect the flower in the bud stage.

2.Corolla : The corolla consists of petals. Petals are usually brightly coloured and help in attracting pollinators.

3.Androecium : It is the male reproductive whorl and consists of stamens. Each stamen consists of a filament and anther.

4.Gynoecium : It is the female reproductive whorl and consists of one or more carpels. A carpel consists of stigma, style and ovary. The ovary contains ovules.

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

Ans. Inflorescence : The arrangement of flowers on the floral axis is termed as inflorescence. A flower is a modified shoot wherein internodes do not elongate and the axis gets condensed.

Two major types of inflorescence are defined - (1) Racemose and (2) Cymose. (1) In racemose type of inflorescence the main axis continues to grow, the flowers are borne laterally in acropetal succession. (2) In Cymose type of inflorescence the main axis terminates in a flower, hence is limited in growth. The flowers are borne in a basipetal order.

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

Ans. Based on the position of the gynoecium on the thalamus and the arrangement of other floral members, flowers are classified as:

Hypogynous flower : In this condition, the gynoecium occupies the highest position, while other floral members are situated below it. The ovary is superior. Examples : Mustard, China rose and Brinjal.
Perigynous flower : In this condition, the gynoecium is situated in the centre and other floral parts are located on the rim of the thalamus at approximately the same level. The ovary is half superior. Example : Rose.
Epigynous flower : In this condition, the thalamus grows upward and completely encloses the ovary. Other floral parts arise above the ovary. The ovary is inferior. Examples : Guava, Cucumber and Sunflower.

3.0NCERT Class 11 Biology – Chapter-Wise Solutions & Explanations

Find chapter-wise NCERT Solutions for Class 11 Biology with simple explanations for every textbook question. Understand important concepts, revise each chapter, and build a strong foundation in Biology for your exams.

Chapter Number	Chapterwise NCERT Solutions
Chapter 1	The Living World
Chapter 2	Biological Classification
Chapter 3	Plant Kingdom
Chapter 4	Animal Kingdom
Chapter 6	Anatomy of Flowering Plants
Chapter 7	Structural Organisation in Animals
Chapter 8	Cell: The Unit of Life
Chapter 9	Biomolecules
Chapter 10	Cell Cycle and Cell Division
Chapter 11	Photosynthesis in Higher Plants
Chapter 12	Respiration in Plants
Chapter 13	Plant Growth and Development
Chapter 14	Breathing and Exchange of Gases
Chapter 15	Body Fluids and Circulation
Chapter 16	Excretory Products and their Elimination
Chapter 17	Locomotion and Movement
Chapter 18	Neural Control and Coordination
Chapter 19	Chemical Coordination and Integration

4.0Key Features of NCERT Solutions for Class 11 Biology Chapter 5

Botanical Terms: Understand important terms such as perigynous, actinomorphic, and syncarpous with clear and simple explanations.
NCERT Examples: Learn the plant examples given in NCERT for different root and stem modifications, leaf types, inflorescences, flowers, fruits, and seeds.
Floral Formulae and Diagrams: Understand the symbols used in floral formulae and floral diagrams of plant families such as Fabaceae, Solanaceae, and Liliaceae.
Comparison of Plant Structures: Learn the differences between racemose and cymose inflorescence and reticulate and parallel venation.
Plant Families: Understand the important characteristics and floral features of Fabaceae, Solanaceae, and Liliaceae.
Prepared by Subject Experts: Solutions are prepared by ALLEN subject experts with accurate botanical terms and explanations based on the NCERT Class 11 Biology syllabus.