Chapter 4

Morphology of Flowering Plants

Solutions

SECTION - A
School/Board Exam. Type Questions
Very Short Answer Type Questions :
1. Which parts in ginger and potato are edible?
Sol. Ginger - Rhizome (stem)
Potato - Tuber (stem)
2. What type of venation occurs in banana?
Sol. Parallel venation
3. What type of aestivation is found in Calotropis?
Sol. Valvate
4. Name the phyllotaxy in Alstonia.
Sol. Whorled phyllotaxy
5. What is the nature of ovary in an epigynous flower?
Sol. Inferior ovary
6. What is the unit of gynoecium?
Sol. Carpel/pistil
7. Write down the name of plant in which leaflets are modified into tendrils.
Sol. Garden pea
8. Which family is commonly called potato family?
Sol. Solanaceae
9. Add the missing floral organs of the given floral formula of fabaceae.

% K(5) A(9)+1 G1

Sol. C1 + 2 + (2)
10. Define internodes and nodes.
Sol. The region of the stem where leaves are borne are called nodes while internodes are the portions between two nodes.

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32 Morphology of Flowering Plants Solutions of Assignment (Set-1)

Short Answer Type Questions :

11. What are trimerous flowers? Give one example.
Sol. When all the floral appendages (whorls) of a flower are in the multiples of three, then the flower is said to
be trimerous.
Examples - Liliaceae family
12. What do the following terms stand for in a floral formula?

, %, P, Br

Sol. – Bisexual flower

% – Zygomorphic flower
P – Perianth
Br – Bracteate
13. Define aleurone layer. Give one example.
Sol. The proteinaceous outer covering surrounding the endosperm is called aleurone layer. It separates the embryo
from the endosperm e.g., monocotyledonous seeds.
14. Differentiate between hypogynous and epigynous flower.
Sol.
Hypogynous flower Epigynous flower

It is a condition where sepals, petals and A condition in which the thalamus is enclosed
stamens all are inserted below the ovary. The within the ovary and all the other floral parts
ovary is said to be superior. arise on the top of the ovary. The ovary in this
case is said to be inferior.
e.g., Mustard
e.g., Guava

15. What are pitcher plants? Give example.

Sol. The plants in which leaves are modified to form pitcher, to trap insects are called pitcher plants. These pitchers
release enzymes to digest the insects and then attain nutrition from them.
16. Rhizome of ginger is like the roots of other plants that grows underground. Despite this ginger is a stem not
a root. Justify.
Sol. Ginger is an underground stem and not root due to the following reasons :
(a) It possesses nodes and internodes.
(b) It bears scaly leaves on the node.
(c) It possesses axillary and apical bud.
17. Name the two plants, belonging to the Solanaceae family, which are used as medicines.
Sol. Belladonna, Ashwagandha.
18. Given below are few floral formulae of some well known plants. Draw floral diagrams from these formulae.

(a) K2+2 C4 A2+4 G(2)

(b) P3+3 A3+3 G(3)

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Solutions of Assignment (Set-1) Morphology of Flowering Plants 33
Sol.

(a) (b)

19. Differentiate between stem tendrils and thorns.

Sol.
Tendrils Thorns
(i) Axillary buds are modified into long, thin (i) Axillary buds are modified into hard,
thread-like spiral structures called straight, pointed structures called
tendrils. thorns.
(ii) It provides support to the weak plants. (ii) It protects the plants from grazing
animals.

20. Draw a labelled diagram of a dicot seed.

Sol. Seed coat
Cotyledon
Plumule

Hilum
Radicle
Micropyle
21. What do you understand by the term venation? Explain its types.
Sol. The arrangement of veins or veinlets in the lamina or leaf blade is known as venation. It occurs in two ways:
(i) Reticulate venation : The venation where veins and veinlets are irregularly arranged or distributed to
form a network is called reticulate venation. It generally occurs in dicot such as peepal, Hibiscus etc.
(ii) Parallel venation : The venation where the veins run parallel to each other and do not form a network
is called parallel venation. It generally occurs in monocots.
Example - Banana.
22. Explain briefly the modification of stem found in Pistia and Eichhornia.
Sol. Pistia and Eichhornia, contain a lateral branch which bear short internodes. In these lateral branches distance
between the nodes decreases and a rosette of leaves and a tuft of roots is found at each node. This is known
as offsets.
23. Explain the vexillary and imbricate aestivation.
Sol. Vexillary aestivation : In vexillary aestivation, the largest petal overlaps the two smaller lateral petals (wings)
which in turn overlap the two smallest anterior petals (keel).
Example - Pea and Bean.
Imbricate aestivation : In imbricate aestivation, margins of petals or sepals overlap each other but not in a
particular fashion or direction.
Example - Cassia, Gulmohur.

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34 Morphology of Flowering Plants Solutions of Assignment (Set-1)

24. Describe the axile placentation with the help of an example.

Sol. Axile placentation : In axile placentation, the placenta is present in the axial position and the ovules are
attached to it in a multilocular ovary.

Example - China rose

25. Describe calyx, corolla and fruit of Solanaceae.

Sol. Calyx : Sepals five, united, persistent, valvate aestivation.

Corolla : Petals five, united, valvate aestivation.
Fruit : Berry or capsule.
26. Write two differences and two similarities in the ovaries of Solanaceae and Liliaceae.

Sol. The ovaries of both Solanaceae and Liliaceae are syncarpous, superior and have axile placentation. The ovary
of Solanaceae is bicarpellary and bilocular whereas the ovary of Liliaceae is tricarpellary and trilocular.
27. What are respiratory roots? How do they help the plant? Give an example.

Sol. The plants growing in mangroves or saline swamps near the seashore respire through modified respiratory
roots called pneumatophores. They come out of the ground and grow vertically upwards to get oxygen for
respiration. e.g., Rhizophora.
28. Tendrils are found in the following plants. Identify whether they are stem tendrils or leaf tendrils.

(a) Cucumber (b) Peas

(c) Pumpkins (d) Grapevine

(e) Watermelons

Sol. (a) Cucumber - Stem tendril

(b) Peas - Leaf tendril
(c) Pumpkin - Stem tendril
(d) Grapevine - Stem tendril
(e) Watermelon - Stem tendril
29. Define root hair. From which region of the root do they arise? What is their function?

Sol. In root, some epidermal cells from the region of maturation form very fine and delicate thread-like structures
called root hair. The root hair increases the surface area for absorption of water and minerals.
30. Draw a well-labelled diagram of a typical leaf and label any five parts.
Lamina
Sol.
Stipule

Petiole
Axillary bud
Leaf base

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Solutions of Assignment (Set-1) Morphology of Flowering Plants 35
Long Answer Type Questions :
31. Describe various root modifications associated with food storage, mechanical support and respiration.
Sol. (i) Modification of root for storage
Tap roots of carrot, turnips and adventitious roots of sweet potato, get swollen and store food.
(ii) Modification of root to provide support
Prop roots : They arise from the branches of stem for providing mechanical support to heavy branches
as pillars e.g., banyan tree.
Stilt roots : They arise from lower nodes of stem to support main axis and enter the soil obliquely
e.g., sugarcane.
(iii) Modification of root for respiration
In some plants such as Rhizophora growing in swampy areas, many roots come out of the ground
vertically upwards to get oxygen for respiration. Such roots are called pneumatophores.
32. Describe briefly the various regions of root.
Sol. Regions of the root
(i) Root cap : At the apex of root a smooth cap-shaped structure is present which is called as root cap.
It is protective.
(ii) Region of meristematic activity : This zone is located a few millimetres above the root cap. The cells
of this region are very small, thin-walled and with dense cytoplasm. They divide repeatedly.
(iii) Region of elongation : The cells of this zone undergo rapid elongation and enlargement and are
responsible the growth of root in length.
(iv) Region of maturation : The cells in this region are differentiated into permanent tissue depending upon
the function they have to perform. Root hairs are also present in this zone which help in absorption of
water.
33. Describe various stem modifications associated with food storage, climbing and protection.
Sol. Stems are modified to store food in some plants. They are underground stem. Due to storage of food materials,
they become thick and fleshy. Different types of underground modified stems are
(i) Rhizome – e.g., Ginger
(ii) Tuber – e.g., Potato
(iii) Corm – e.g., Colocasia
Stem tendril : Stem tendrils are slender and spirally coiled structures which develop from axillary buds and
help to climb.
e.g., Grapevines
Modification of stem for protection
In some plants, axillary buds of stems may get modified into woody, straight and pointed thorns. They protect
plants from browsing animals.
e.g., Citrus
34. What is a leaf? Where does it arise from? How is it borne on a stem? What is its function?
Sol. A leaf is a green, flat, thin expanded lateral outgrowth of the stem. It originates from the shoot apical meristem.
It is borne on the node of the stem in an acropetal order (i.e., youngest leaves towards the growing point
and the oldest towards the base of the parent stem). Leaf bears a bud which later develops into a branch.
The bud is present at the axil of the leaf.
Leaves are green in colour due to the presence of photosynthetic pigment, chlorophyll. Chlorophyll is essential
for absorbing sunlight needed for the process of photosynthesis by which the leaves prepare their own food.
Leaves are the most important vegetative organ for photosynthesis.
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36 Morphology of Flowering Plants Solutions of Assignment (Set-1)

35. What is a compound leaf? Explain its two types with the help of example and diagram.

Sol. Compound leaf : The leaf in which the lamina or leaf blade of the leaf is completely broken into distinct
leaflets is called compound leaf. The leaf has incision which reaches the midrib. Compound leaf contains a
bud at the axil of the petiole but is absent in the axil of leaflets. The compound leaves are of two types :
(i) Pinnately compound leaf : In pinnately compound leaf, the midrib forms a common axis called rachis.
A number of leaflets are present on common axis.
Example - Neem.

(ii) Palmately compound leaf : In palmately compound leaf, the leaflets are attached to a common point
i.e., at the tip of the petiole. The tip of the petiole bears all the leaflets in a form of a bunch or cluster.
Example - Silk cotton.

36. Explain the different types of floral symmetry.

Sol. The floral symmetry can be of three types :

(i) Radial symmetry : In radial symmetry any radial vertical plane, passing through the centre divides the
flower into two equal radial (vertical) halves. The two vertical halves are mirror images of each other. The
flowers having radial symmetry are called actinomorphic flowers.
Example - Mustard flowers.
(ii) Asymmetric symmetry : In asymmetric symmetry, a radial vertical plane passing through the centre
cannot divide the flower into two equal halves. The flower is irregular and asymmetric.
Example - Canna
(iii) Bilateral symmetry : In bilateral symmetry, only one, single vertical plane passing through the centre
divides the flower into two equal halves, which are mirror images of each other. In bilateral symmetry
only one plane divides the flower into two equal halves. The flowers having bilateral symmetry are said
to be zygomorphic.
Example - Peas, gulmohar, bean, Cassia.
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Solutions of Assignment (Set-1) Morphology of Flowering Plants 37
37. Write a short note on fourth whorl of a flower.
Sol. Gynoecium is the fourth and last whorl of the flower. It is the female reproductive part of a flower which is
composed of one or more carpels. A carpel has three parts namely :
(i) Ovary : Ovary is the lower part of the carpel which bears one or several ovules. These ovules later
matures into seeds after fertilisation. The ovules are attached to a flattened and cushion-like structure
called placenta. The ovary has one or more chambers or loculi. The wall of the ovary after fertilisation
forms the pericarp (fruit wall). Ovules develop in to seed after fertilization.
(ii) Style : The tube-like structure which connects the stigma and the ovary is called style. It lie above the
ovary in a carpel.
(iii) Stigma : Stigma is generally situated at the tip of the style. During pollination the pollens are transferred
from the anther to the stigma. The stigma acts as the receptive organ for pollen grains.
38. Explain with diagram the placentation found in pea and mustard.
Sol. (i) Marginal placentation : The placenta forms a ridge along the ventral suture of the ovary. The ovules
are borne in two alternate rows along the ridge.
Example - Pea
(ii) Parietal placentation : The ovary is one-chambered (unilocular) but become two-chambered due to the
formation of the false septum. The ovules develop on the inner wall of the ovary or on the peripheral part.
Example - Mustard

A B
39. Tabulate the essential differences in the structure of a dicotyledonous and monocotyledonous seed.
Sol.
Dicotyledonous seed Monocotyledonous seed

(i) It contains two cotyledons. (i) It contains only one cotyledon.

(ii) It is generally non-endospermic with few (ii) It is generally endospermic.
exception.
(iii) Aleurone layer is absent. (iii) Aleurone layer may present.
(iv) The seed coat are separated from the (iv) The seed coat is generally fused with the
fruit wall. fruit wall.

40. Write the floral characters of fabaceae.

Sol. Floral Characters of Fabaceae family
Inflorescence : Racemose.
Flower : Bisexual, zygomorphic.
Calyx : Sepals five, gamosepalous, imbricate aestivation.
Corolla : Petals five, polypetalous, papilionaceous, consisting of a posterior standard, two lateral
wings, two anterior ones forming a keel (enclosing stamens and pistil), vexillary aestivation.
Androecium : Ten, diadelphous, anther dithecous.
Gynoecium : Ovary superior, monocarpellary, unilocular with many ovules, style single.
Fruit : Legume, seed : one to many, non-endospermic.

Floral formula : K(5) C1+2+(2) A(9)+1 G1

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38 Morphology of Flowering Plants Solutions of Assignment (Set-1)

41. Why are the plants of Solanaceae family important to us?

Sol. Economic Importance of Solanaceae family
a. Source of food : Example - Potato, tomato
b. Spices : Chilli
c. Fumigatory plant : Tobacco
d. Medicine : Belladonna
42. Write any 10 symbols and what they stand for, used in a floral formula.
Sol. Symbols Stand for
Br Bracteate
K Calyx
C Corolla
P Perianth
A Androecium
G Gynoecium
G Superior ovary
G Inferior ovary
Male
Female
Bisexual
Actinomorphic
% Zygomorphic

43. Why are leaves modified in some plants? Write any two modifications of leaves.
Sol. Leaves are generally responsible for the process of photosynthesis, transpiration, gaseous exchange etc. But
at some places where the conditions are unfavourable, leaves get modify and perform other functions such
as storage, protection, support, defence etc. Different modifications that occur in leaves are :
(i) Leaf tendrils : In some plants, leaves modify into long, slender, thread-like sensitive structures called
tendrils. Tendrils coil around a support to which they come in contact and help the plant while climbing.
The tendrils are sensitive to touch. Their main function is to provide support to the climbing plants.
Example - Peas
(ii) Spines : In some plants such as cactus, leaves modify into small, sharp-pointed structures which reduce
transpiration and protect the plants from browsing animals. The sharp pointed structures are called spines.
44. (a) Give the reproductive unit in angiosperms.
(b) What is perianth? Give two examples.
(c) Differentiate between radial and bilateral symmetry.
Sol. (a) Flower
(b) When calyx and corolla are not distinct, the undifferentiated structure is called perianth.
(c)
Radial Bilateral
When a flower can be divided into two equal When a flower can be divided into two similar
radial halves in any radial plane passing halves only in one particular vertical plane, it
through the centre, it is said to be is zygomorphic or bilateral.
actinomorphic or radial.
e.g., Pea
e.g., Mustard

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Solutions of Assignment (Set-1) Morphology of Flowering Plants 39
45. Write a short note on endosperm, embryo and seed coat found in seed of maize plant.
Sol. Endosperm
In a monocot seed the endosperm is bulky. It is covered by a protein layer. The proteinaceous outer covering
surrounding the endosperm is called the aleurone layer. Layer separates the embryo from the endosperm.
The endosperm stores food material which provides nourishment and nutrition to the growing embryo.
Embryo
The embryo is present in the seed coat. It contains a cotyledon and a small axis called the embryonal axis.
This axis contains plumule at one end and radicle at the other. The plumule which gives rise to the shoot
system and is enclosed in a protective sheath called coleoptile. The radicle which gives rise to the root
system and is enclosed in a sheath called coleorhiza.
Seed coat
The protective membrane present over the seed is called the seed coat. It surrounds the seed and enclose
the embryo and the endosperm. Seed coat is membranous and is generally fused with the fruit wall. The outer
wall of the fruit (pericarp) is fused with the seed coat.

SECTION - B
Model Test Paper

Very Short Answer Type Questions :

1. There may be a variation in the length of filaments of stamens within a flower. Give two examples.
Sol. Salvia, mustard
2. Write the floral formula for family Liliaceae.

Sol. P3 + 3 A3 + 3 G(3)

3. Name the fumigatory plant belonging to the family Solanaceae.

Sol. Tobacco
4. What is the ploidy level of aleurone layer?
Sol. Triploid
5. Name the inflorescence in which the flowers are arranged in a basipetal manner.
Sol. Cymose inflorescence
6. What is mesocarp?
Sol. It is the middle layer of the pericarp. It is present between the epicarp and endocarp.
7. What is the fate of ovule and ovary after fertilisation?
Sol. After fertilisation, the ovules develop into seeds and ovary develops into a fruit.
8. Which drupe has a fibrous mesocarp?
Sol. Coconut

Short Answer Type Questions :

9. What is the family of Aloe? Why is it important?

Sol. Aloe is a source of medicine. It is a member of Liliaceae.

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40 Morphology of Flowering Plants Solutions of Assignment (Set-1)

10. Explain valvate aestivation.

Sol. In valvate aestivation, margin of the sepals or petals present in a whorl just touch each other. There is no
overlapping between the two sepals or petals.
Example - Calotropis
11. Explain alternate phyllotaxy with the help of an example.
Sol. The phyllotaxy in which single leaf is present at each node in an alternate fashion is called alternate phyllotaxy.
Example - China rose, mustard, sunflower.
12. Describe the type of leaf present in neem.
Sol. Neem has pinnately compound leaf. Midrib forms a common axis called rachis.
13. Diagrammatically explain the difference between parallel and reticulate venation.
Sol.

14. What do you understand by asymmetric symmetry?

Sol. In asymmetric symmetry, a radial vertical plane passing through the centre cannot divide the flower into two
equal halves. The flower is irregular and asymmetric.
Example - Canna.
15. What is stigma? Why is it important?
Sol. Stigma is a part of carpel. It is situated at the tip of the style. It receives pollen grains providing male gametes
for fertilisation. During pollination, pollen grains are transferred from the anther to the stigma.
Short Answer Type Questions :
16. Draw the floral diagram for the family Solanaceae.
Sol.

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Solutions of Assignment (Set-1) Morphology of Flowering Plants 41
17. Which symbols are used to represent the following in a floral formula?
(a) Inferior ovary
(b) Calyx
(c) Male
(d) Zygomorphic flower
(e) Perianth
(f) Gynoecium

Sol. (a) Inferior ovary – G

(b) Calyx – K
(c) Male –
(d) Zygomorphic – %
(e) Perianth – P
(f) Gynoecium – G
18. Describe the function of a stem.
Sol. (i) Stem bears and support leaves, flowers and fruits.
(ii) It conducts water and mineral salts from roots to the leaves, fruits and different parts of a plant.
(iii) The food manufactured in the leaves is transported to the roots, fruits and organs of storage through the
stem.
19. Explain the modified stem – stolon, in brief.
Sol. Stolon : It is subterranean long lateral branch arising from base of the stem. It first grows obliquely upward
and then bends down to the ground surface. e.g., Jasmine.
20. What is a floral diagram? Explain with a diagram.
Sol. A floral diagram provides information about the number of parts of a flower, their arrangement and the relation
they have with one another. The position of the mother axis with respect to the flower is represented by a
dot on the floral diagram in the centre.

21. Give two examples that develop from different part of the angiospermic plant other than radicle. Name the roots
which are modified for respiration.
Sol. Stilt roots : They arise from lower nodes to stem e.g., Maize.
Prop roots : They arise from the branches of stem e.g., Banyan.
Pneumatophores help in respiration e.g., Rhizophora.
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42 Morphology of Flowering Plants Solutions of Assignment (Set-1)

Long Answer Type Questions :

22. (a) What is fruit?
(b) Define parthenocarpic fruit.
(c) Describe various zones of fruit by taking any fleshy fruit.
Sol. (a) Fruit is a ripened ovary, developed after fertilisation.
(b) If fruit is formed without fertilisation of the ovary, it is called a parthenocarpic fruit e.g., Banana.
(c) A fruit consists of a wall or pericarp and seeds. The pericarp may be dry or fleshy.
Mango is a fleshy fruit. In mango pericarp is thick and fleshy. It is differentiated into outer epicarp, the
middle mesocarp and the inner endocarp. The mesocarp is edible in mango.
23. Distinguish between families Solanaceae, Liliaceae and Fabaceae on the basis of gynoecium characteristics.
Also write economic importance of any one of the above family.
Sol.
Criteria Solanaceae Liliaceae Fabaceae
Gynoecium Bicarpellary, syncarpous, Tricarpellary, syncarpous, M o n o c a r p e l l a r y, o v a r y
ovary superior, bilocular, ovary superior, trilocular with superior, unilocular with many
placenta swollen with many many ovules. ovules, style single.
ovules.

Economic importance of family fabaceae :

(i) Sources of pulses – e.g., Gram, arhar

(ii) Edible oil – e.g., Soyabean, groundnut

(iii) Dye – e.g., Indigofera

(iv) Fibres – e.g., Sunhemp

(v) Fodder – e.g., Sesbania, Trifolium

(vi) Ornamental plants – e.g., Lupin, sweet pea

(vii) Medicine – e.g., Muliathi

  

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