5 MORPHOLOGY OF FLOWERING PLANTS

CHAPTER NO.5 MORPHOLOGY OF FLOWERING PLANTS

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INTRODUCTION:MORPHOLOGY: it is branch of biology dealing primarily with the study of form, size, structure and relative position of different organs and their specific structural features. It is of two types: External and Internal.External morphology means the study of external form, size, structure and relative position of different organs and their specific structural features.Internal morphology means the study of internal form and structure of organisms. It has two parts; Anatomy and Histology.Darwin asserted that Morphology is the soul of Biology.

MORPHOLOGY OF ROOT:Root is generally non green, underground, positively geotropic, positively hydrotropic and often negatively phototropic descending cylindrical axis of plant body which develops from radicle of the embryo.Roots primarily help in anchorage of the plant, absorption of water and minerals from the soil and secondary functions like respiration, floatation, photosynthesis,

climbing, storage, reproductory, extra support etc.

PARTS OF A ROOT

1.Root Cap.

2.Meristematic Zone

3.Zone of Elongation 4.Root Hair Zone

5.Zone of Maturation

The root is covered at the apex by a thimble-like structure called the root cap. Its main function is to protect the tender apex of the root that makes its way through the soil. Region of meristematic activities found above root cap.The region of elongation is found at the place where the newly formed cells increases in length and by this the lengthening or elongation or root takes place .From the region of maturation epidermal cells form very fine and delicate,thread-like structures called root hairs. These root hairs absorb water and

minerals from the soil.

ROOT SYSTEMS:There are two main type of root system.

1. Tap Root System. Tap root is the primary root which develops from radicle of embryo and persist throughout life of plant.

2. Adventitious Root System. It is complex formed by roots that develop from any parts of the plant other than radicle.

The main functions of the root system are the absorption of water and

minerals from the soil, providing a proper anchorage to the plant parts, storing reserve food material, and synthesis of plant growth regulators.The primary roots and their branches constitute the tap root system, as in the mustard plant. There are short-lived primary roots found in monocot plants,which replaced by a large number of roots that originate from the base of the stem constitute the fibrous root system, as seen in the wheat plant.The roots arise from parts of the plant other than the radicle and are called adventitious roots. In some plants, like grass,Corn, and the banyan tree.

PART:A VERY SHORT ANSWER TYPE QUESTIONS:

A. MULTIPLE CHOICE QUESTIONS:

Q1 Root bears only:

(a)nodes only

(b) internodes only

(d) none

Q2 In adventitious roots, what is absent?

(a)Root Hairs

(b) Root Cap

(d) All of these

Q3 Contractile roots are found in:

(a)Bulb

(b) Tuber

(d) Corm

Q4 Haustoria help in survival of:

(a)jepiphytes

(b) saprophytes

(d) all of these

Q5 Mangrooves consist of:

(a)Heliophytes

(b) Helophytes

(d) Hygrophytes

Q6 The lenticels in respiratory roots are called

(a)Pneumatophores

(b) Stomata

(d) Hydathodes

Q7 Root nodules are found on:

(a)Primary root

(b) Secondary root

(d) All above

Q8 Adventitious roots are recognized by:

(a)Function

(b)Origin

(d) Anatomy

Q9 Black pepper is:

(a)Root climber

(b) Leaf climber

(d) Tendrillar climber

Q10 Partial root parasite is:

(a)Viscum

(b) Cuscuta

(d) Loranthus

B. FILL IN THE BLANKS:

1. Lateral roots arise from .............

2. The cells of the root cap are rich in.......... and secrete........

3. Roots arising from callus in tissue culture are...........

4. In maize and sugarcane ............roots arise from lower nodes.

5. A Tap root is always...........geotropic and..........hydrotropic.

C. TRUE/ FALSE:

1. InPinus root system is cymose tap root system.

2. Root Cap is absent in Lithophytes.

3. Roots store food in meristematic zone.

4. Tap roots are common in monocots.

5. Velamen tissue occurs in Haustorial roots of orchids.

ANSWER KEY: PART-A

A. MULTIPLE CHOICE QUESTIONS:

1.d Since nodes and internodes occur on stems.

2.d Adventitious roots donot arise from radicle of embryo,they are false roots

3. d Corms have contractile roots.

4. c Haustoria help in survival of parasitic plants

5. c Mangrooves are plants found in saline water, hence fall in category of Halophytes

6.c Pneumathodes is another name for lenticels

7. d Root nodules occur both on primary and secondary roots

8. b Adventitious roots are characterized from source of Origin

9. a Black pepper is root climber,as roots are modified for climbing

10. c Santalum album is under category of partial root parasite as it just obtains water nourishment from host plants.

B. FILL IN THE BLANKS:

1. Pericycle

2. Golgi Bodies, Mucilage

3. Adventitious Roots

4. Stilt Roots

5. Positively, Positively

C. TRUE /FALSE:

1. TRUE

2. FALSE Root Caps are absent only in Epiphytes.

3. FALSE Roots store food in cell differentiation region

4. FALSE Tap Root System is characteristic feature of dicots and not of Monocots

5. TRUE

PART: B SHORT ANSWER TYPE QUESTIONS:

Q1. Why potatoes and sweet potatoes are called as tubers?

Q2. Write short notes for the following modifications of roots

AFusiform BTuberous C Prop root

Q3. List various function of roots.

PART: C LONG ANSWER TYPE QUESTIONS:

Q1. Enumerate difference between Tap Root System and Adventitious

Root System.

Q2. Give suitable example of root modification for storage of food [Both Tap and Adventitious roots]

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INTRODUCTION:Dear students, today we will study about Morphology of stem and its modifications.PLANT STEM - A stem is one of two main structural axes of a vascular plant,the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and

phloem, stores nutrients, and produces new living tissue.

MORPHOLOGY OF STEM :- Stem morphology is simple. Its components are

nodes (places where leaves are/were attached) and internodes, long or short (in the last case, plant sometimes appears to be stem less, rosette-like).Stems are different by the type of phyllotaxis. The phyllotaxis refers to the arrangement of leaves. If there is one leaf per node, it is a spiral (alternate) arrangement. Two leaves per node means opposite arrangement. Opposite leaves can be all in the same plane or each pair can rotate at 90. If there are more than two leaves per node, it is a whorled arrangement, and each whorl can also rotate. Different types of leaves arrangements are as given in fig 1.0

Some of the most important types of modifications of stem are as follows:

|. Underground modifications of Stem

Il. Subaerial modifications of Stem

Ill. Aerial modifications of Stem

Underground modifications of Stem:Many plants produce underground stems for perennation and food storage. They produce aerial shoots annually.Although they resemble roots superficially but can be distinguishable from roots by the presence of following features:

(i) Presence of nodes and internodes.

(ii) Presence of scale leaves, buds and adventitious roots at the nodes.

(iii) Internal structure resembles that of aerial stem and not of root.Some underground modified stems are as:

1, Rhizome:It is fleshy, non-green underground stem. It has distinct nodes and internodes.The nodes bear dry scale leaves with axillary buds. Terminal buds also present. Adventitious roots arise from the lower side. The rhizome that grow obliquely is called root stock rhizome (e..g., Alocasia, Dryopteris, Banana etc.)and when grow horizontally is called straggling rhizome [e.g. Ginger, termeric,etc.).

2. Corm:It is a condensed form of rhizome growing in vertical direction. It is more or less spherical with a flattered base. The corm has distinct circular nodes and internodes.The nodes bear scale leaves and axillary buds. Adventitious roots arise either from

its base or all over the body. Examples- Colocasia, corcus, Amorphophallus.

3. Tuber:Stem tuber is a swollen tip of an underground lateral Stem (Stolon). It is covered by a corry skin with a number small depressions called eyes’. Each eye represents a node, bearing one or more buds subtended by a leaf scar (= scale leaf). A big scar at

one end (heel end) of a potato marks its attachment to the stolon. Adventitious roots are usually absent e.g., Potato.

4. Bulb:It is a highly condensed discoid stem .its upper surface a terminal bud and many fleshy scale leaves are present. A cluster of adventitious roots arise from the base of the bulb. The bulbs may be tunicated or scaly. A tunicated bulb is covered by a sheath of dry membranous scale leaves called tunic, e.g., onion and garlic. In

case of garlic, the bulb consists of an aggregate of bulblets or cloves, each covered by its individual tunic.

The weak sub-aerial stems are modified into following four types:

1. Runner:It is a creeping stem with long internodes, running horizontally on the soil surface.The nodes bear axillary buds, scale leaves and adventitious roots. Runner arises from an axillary bud. A mother plant often produces a number of runners in all direction. Runners break off and grow into individual plants, and thus help in

vegetative propagation. Examples - C-Cynodon (Lawn grass), Oxalis (Wood sorrel)

2. Sucker:It arises from the basal, underground part of the main stem. It grows horizontally for a distance under the soil and then emerges obliquely upwards. It develops a leafy shoot and adventitious roots before separating from the mother plant. The common sucker-bearing plants are Chrysanthemum (Or. Sebati), Mentha (Or podina), pineapple etc.

3. Stolon:It is a weak lateral branch that arises from the base of main stem. After growing aerially for some time it bends downwards to touch the ground, where its terminal bud gives rise to a new shoot and adventitious roots. The common stolon bearing plants are Jasmine, Colocasia, and Vellisneria etc.

4, Offset:It is a short runner with one internode long. It originates from leaf axil, grows as a short horizontal branch.It produces a rosette of leaves above and adventitious roots below. Offsets art generally found in aquatic plants like Pistia (water lettuce), Eichhornia (water hyacinth), Houseleek etc.

Ill, Aerial modifications of Stem:In certain plants, the aerial stem or buds get modified to perform special functions like climbing, protection, food storage, vegetative propagation etc.The various aerial modifications are as follows:

1. Stem tendrils:Stem or its branches get modified into green thread like leafless structures called tendrils which are meant for climbing. These may be branched or un-branched. A scale leaf is always present at the point of branching of the tendril. E.g Cuscus,grape vine etc.

2. Thorns:These are straight, pointed, hard or woody structures sometimes they bear leaves,flowers or even may be branched. Thorns are used as organs of defence or climbing (e.g. Bougainvillea) and check transpiration.

3. Phylloclades:These are fleshy, green flattened or cylindrical branches of unlimited growth. The leaves are modified into spines or scales to check transpiration. They take part in photosynthesis and store water. These are seen in xerophytic plants like Opuntia,

Euphorbia etc.

4. Cladodes or Cladophylils;These are green cylindrical or flattened leaf-like branch of limited growth. In Asparagus, the cladodes are one internode long. They help in photosynthesis.

5. Bulbil:These are modified vegetative or floral buds with stored food and meant for vegetative propagation. In Dioscorea, bulbils are condensed axillary buds while in Agava and lily the floral buds develop into bulbil. They detach to become new plants.

LET US KNOW WHAT WE HAVE LEARNT!

PART: A_VERY SHORT ANSWER TYPE QUESTIONS:

A. Multiple choice questions :

1. Underground stems are primarily meant for:

a. vegetative reproduction

b. perennation

c. protection from strong light

d. anaerobic respiration

2. Thorn is stem structure because it is:

a. axillary

b. like a branch

c. hard pointed structure

d. aerial

3. A stem functioning as photosynthetic organ is:

a. phyllode

b. phylloclade

c. culm

d. caudex

4. Sucker is a horizontal stem branch found in:

a. gloriosa

b. chrysanthemum

c. grass

d. strawberry

5. Stem is specialized to perennate and store food in:

a. groundnut c. beet

b. ginger d. sugarcane

B. Fill up's:

1. Potato tuber is an underground stem because it bears. ........... on the nodes.

2. Thorns, spines and prickles are organs of ...............

3. Potatos are cultivated by means of ...............

C. True/False

1. The plant stores food in stem in brinjal.

2. Primary function of stem is anchorage.

ANSWER KEY: PART-A

A. Multiple choice questions :

Ans.1. __b (the ability to survive longer)

Ans.2. a (arise from the axil, the junction of leaf and stem.)

Ans.3. b (phylloclade: the green coloured stem and perform photosynthesis. )

Ans.4. _b (chrysanthemum)

Ans.5. b (ginger is underground stem. It sores food and can perennate or lasts longer.)

B. Fill up's:

1. bud

2. defence

3. tubers

C. True/False:

1. False; (the food is stored in fruit in brinjal.)

2. False: (the primary functions of stem are to support leaves and branches, to conduct water and minerals. )

PART: B__ SHORT ANSWER TYPE QUESTION:

1. Discuss the importance of stem modification in plants.

2. Write a short note on aerial modifications of stem in plants.

3. Write a short note on

a. phylloclades

b. cladodes

4. Label the figure: A, B, C

PART: C_LONG ANSWER TYPE QUESTION:

1. What are various types of stem modifications in plants? Explain with suitable examples.

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INTRODUCTION:Leaves are the most important vegetative organ for Photosynthesis. Leaves are called the “Food factory of plants” or “Kitchen of Plant”.Leaf is generally green photosynthetic lateral flattened structure borne on stem. It develops at the node of stem and bears a bud at its axil. The axillary bud later develops into a branch. Leaves originate from shoot apical meristem and are arranged in acropetal order (new leaves at the apex and

older at the base).

Characteristics of Leaf:

1. The leaf is a lateral dissimilar appendage of stem.

2. It is Exogenous in origin.

3. The Growth of leaf is limited.

4. A leaf has three main parts- Leaf base, petiole and lamina. In addition, it may possess two lateral outgrowths of the leaf base, called stipules.

Parts of Leaf:

Typical leaf has three main parts:

Leaf base: Leaf is attached to stem by leaf base may bear two lateral small leaf like structures called stipules. In monocotyledons the leaf base expands into a sheath covering the stem partially or wholly called sheathing leaf base.

Petiole: It is cylindrical or sub-cylindrical stalk which connect leaf base with lamina.Petiole help hold the blade to light.

Lamina: It is the green expanded part of the leaf with veins and veinlets.There is usually a middle prominent vein known as Midrib. Veins provide mechanical strength and also act as channel of transport for water, mineral and food.

The arrangement of veins and the veinlets in the lamina of leaf is termed as venation.

There are three types of venations- Reticulate, Parallel and furcate.

1.Reticulate Venation: Veins and veinlets form a fine network or reticulum by their close juxtaposition. Reticulate venation is of two subtypes unicostate and multicostate.

(i) Unicostate reticulate venation- A single principal vein or midrib runs from base to the apex of the lamina. Lateral veins arise from its sides along the whole length.eg: China rose, Mango, Peepal etc.

(ii) Multicostate reticulate venation- Many principal veins or ribs develop from base of lamina and proceed in an arched fashion towards the apex or the margins.eg:Zizyphus, Grape Vine etc.

2. Parallel Venation: The venation is without reticulation because the veinlets are fewer and far apart. The veins run parallel. It is of two types, unicostate and multicostate.

(i) Unicostate parallel venation: A single principal vein or midrib develops from base and runs towards apex of the lamina. On the way it gives rise to a number lateral veins on both the sides. The lateral veins proceed towards the margins,running parallel to one another eg: Banana, Canna

(ii) Multicostate parallel venation: A number of principal veins or midribs arise from the lamina base and proceed towards either the apex or the margins in an arched fashion. Eg: Grass, Bamboo, Maize, Wheat.

3.Furcate Venation: The veins neither run parallel nor form reticulations. They are dichotomously branched. Eg: Circeaster

In many plants, leaves get modified to perform some special functions other than the normal ones, such as photosynthesis and transpiration.

Sometimes these modifications are in response to certain environmental

conditions. Some of the important modifications are given below:

1. Storage Leaves: Some plants of xerophytic habitats and members of the family Crassulaceae generally have highly thickened and succulent leaves with water storage tissue. These leaves have large parenchymatous cells with big central vacuole filled with hydrophilic colloid. This kind of adaptation helps plants to conserve very limited supply of water and resist desiccation (drying up).

2. Leaf Tendrils: In weak- stemmed plants, leaf or a part of leaf gets modified into green threadlike structures called tendrils which help in climbing around the support. E.g.: Grape

3. Leaf-spines: Leaves of certain plants become wholly or partially modified for defensive purpose into sharp, pointed structures known as spines. Eg: Opuntia, date-palm, dagger plant (Yucca), Mexican poppy (Argemone),Amercian aloe (Agave), Indian aloe (Aloe)

4. Scale-leaves: Typically, these are thin, dry, stalkless, membranous

structures, usually brownish in color or sometimes colorless. Their function is to protect the axillary bud that they bear in their axil. Sometimes scale-leaves are thick and fleshy, as in/onion; then their function is to store up water and food. Scale-leaves are common in parasites, saprophytes,underground stems, etc.

5. Leaflet Hooks: In Bignonia unguiscati the three terminal leaflets of leaf get modified into claw like hooks which help in climbing.

6. Insect Catching Leaves: In insectivorous plants, the leaves are especially adapted to catch and digest insects to fulfil their nitrogen requirement.

Phyllotaxy:Phyllotaxy is the pattern of arrangement of leaves on the stem or branch. This is usually of three types- alternate, opposite and whorled. In alternate type of phyllotaxy, a single leaf arises at each node in alternate manner, as in China rose.In opposite type, a pair of leaves arise at each node and lie opposite to each other

as in Calotropis and guava. If more than two leaves arise at a node and form a whorl, it is called whorled as in Alstonia.

PART:A_VERY SHORT ANSWER TYPE QUESTIONS

a) Multiple choice questions: -

A) Functions of leaf are:

a) Photosynthesis

6) Transpiration

c) Exchange of gases

d) All of above

B) Type of venation in Banana:

a) parallel

b) reticulate

c) furcate

d) none

C) Arrangement of leaves on the stem or branch is called:

a)inflorescence

b) phyllotaxy

c) venation

d) none

D) Leaf having stipule is called:

a) exstipulated

b) stipulated

c)botha&b

d) none

E) Leaf with single, entire or incompletely divided lamina is called:

a) palmately compound leaf

b) simple leaf

c) compound leaf

d) all of above

b) Fill ups: -

a) Leaves are called the .

b) The arrangement of veins and the veinlets in the lamina of leaf is termed as

c) True/ False: -

a) Sheathing leaf base is found in monocot.

b) The leaf is a green, flat, thin lateral structure borne on the stem.

c) Leaf modified in form of spines reduces photosynthesis.

ANSWER KEY: PART-A

a) Multiple choice questions:

Ans A) d) All of above. (Leaves are major site of photosynthesis, Transpiration and gaseous exchange also takes place through them).

Ans B) a) Parallel. (Banana is a monocotyledonous herb and leaf venation is parallel in monocots).

Ans C) b) Phyllotaxy. (Phyllotaxy is arrangement of leaves on stem or branch).

Ans D) b) Stipulated. (Leaf without stipule is called exstipulate).

Ans E) b) Simple leaf. (Simple leaves have single, entire or incompletely divided lamina).

b) Fill ups:

Ans a) Leaves are called the food factory of plants because photosynthesis occur in leaves.

Ans b) The arrangement of veins and the veinlets in the lamina of leaf is termed as venation.

c) True/False:

Ans a) True- monocot leaves have sheathing leaf base.

Ans b) True- Leaves are flat, green and lateral structures.

Ans c) False- Leaves modified in form of spines reduce transpiration.

PART: B_ SHORT ANSWER TYPE QUESTIONS

a) How simple leaves differ from compound leaf?

b) Define Insectivorous plants?

c) Why leaf is called “Kitchen of plant’?

PART: C LONG ANSWER TYPE QUESTIONS

a) Explain phyllotaxy with examples.

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INTRODUCTION:Dear students as we know:A plant looks beautiful as it has a different arrangement of flowers on it.The arrangement of flowers on floral axis is called INFLORESCENCE.

The stem that bears a single flower or an inflorescence is called the peduncle.The peduncle of an inflorescence may have smaller stems called ' pedicels.

FUNCTION OF INFLORESCENCE: - The most important function of

inflorescence is it makes flowers more noticeable to pollinating agents (insects/birds) so that chances of cross pollination are high.

TYPES :; Inflorescence is of two main types:

1) Racemose

2) Cymose

1) Racemose: - Main axis of inflorescence does not end in a flower but

continues to grow. It is also called Indefinite Inflorescence.

The development of flower is acropetal (older towards base and younger toward apex),if the peduncle is elongated.

The opening of flower is centripetal (older toward periphery and younger toward centre), if the peduncle is flattened.

EXAMPLES- Radish, cauliflower, wheat, sunflower

Edible part of CAULIFLOWER is inflorescence.

2) CYMOSE: -Main axis ends in a flower and is thus of limited growth. It is also called Definite Inflorescence.The development of flowers is basipetal (younger toward base and

older toward apex),if the axis is elongated. The opening of flower is centrifugal, if the floral axis is condensed.

EXAMPLES- Solanum nigrum.

It is formed by the condensation of group of flowers.

It is of following types:

[ER It looks like a single flower,where a cup shaped involucre encloses a single female flower and a number of male flowers.Each male flower is represented by a single stamen.e.g.: Euphorbia pulcherrima

[RE Hypanthodium has a flask shaped receptacle with an apical opening.

The flowers developed on inner wall of the hollow cavity.Internally the receptacle bear male flowers towards the pore.Female flowers towards the base.Gall flowers in between the two groups.e.g.- Ficus ( Banyan ,Fig )

LET US KNOW WHAT WE HAVE LEARNT!

PART: A__ VERY SHORT ANSWER TYPE QUESTIONS:

a) Multiple choice questions:

1) Arrangement of flower on floral axis is termed as:

(a)phyllotaxy

(b)venation

(d) aestivation

2) Cymose inflorescence is present in:

(a)gram

(b)Mustard

(c)Solanum

(d)Wheat

3) In raceme the flowers are:

(a)arranged in basipetal succession

(b)arranged in acropetal succession

(d) of the same sexes

4) Hypanthodium is a characteristic inflorescence of:

(a)Mulberry

(b) Ficus

(d)Pine apple

5) Cyathium is found in:

(a)Ficus

(b)Morus

(d)Solanum

b) Fill ups: -

1. Edible part of cauliflower is -----—---—-.

2. In cymose type inflorescence flowers are borne in-----------

succession.

3. The stem that bears a single flower or an inflorescence is called

the -—--.

c) True / False

1. Cymose inflorescence shows limited growth.

2. In Hypanthodium inflorescence gall flowers are present toward

the base of receptacle.

ANSWER KEY: PART-A

1) Ans (c) inflorescence( Arrangement of flower on floral axis is termed as inflorescence)

2) Ans (c) Solanum { e.g of cymose inflorescence)

3) Ans (b) arranged in acropetal succession (flower is acropetal-older

towards base and younger toward apex).

4) Ans (b) Ficus ( Ficus bear special kind of hypanthodium

inflorescence)

5) Ans (c) Euphorbia (Cyathium is a cup shaped involucre encloses a

single female flower and a number of male flowers.)

1) Edible part of cauliflower is inflorescence.

2) In Cymose type inflorescence flowers are borne in basipetal

succession.

3) The stem that bears a single flower or an inflorescence is called the peduncle.

1) True Cymose inflorescence shows limited growth.

2) False Gall flowers are present in between male and female flowers)

PART: B SHORT ANSWER TYPE QUESTIONS:

1) Differentiate between Racemose and Cymose inflorescence.

2) Define inflorescence.

3) What is the important function of inflorescence?

4) Draw the labeled diagram of Hypanthodium inflorescence.

PART:C LONG ANSWER TYPE QUESTIONS:

1. Define the term inflorescence. Explain the basis of different type’s inflorescence in flowering plants.

A55

INTRODUCTION:Every living organism has a fixed form and it is because of this reason that we are able to differentiate most of them just due to their external structure.The study of external structures of organs is called external morphology,and internal structures as internal morphology or anatomy.Let us discuss today about morphology of a flower.

FLOWER:The flower is a highly modified shoot meant essentially for the

sexual reproduction of the plant.A flower is generally borne on the lateral side of the peduncle at a node in the axil of a leaf structure called bract.A flower arising in the axil of a bract is called bracteates and if the bract is absent at the base of flower is said to be a ebracteate.The stalk of the flower is called pedicel, which exposes the flower in favourable position for pollination and the flower is called pedicellate.The mode of arrangement of flowers on a specialized branch on the top of the plant which bears flowers is called inflorescence.Calyx is the outer most whorl of the flower, which supports to the floral parts of flowers ,and protect the internal organs of flower.

Atypical flower has four different kind of whorls arranged on swollen end of stalk/pedicel called thalamus.

These are: CALYX COROLLA ANDROCIUM GYNOCIUM POSITION OF FLORAL PARTS ON THALAMUS:

. HYPOGYNY: When the various whorls of flower are arranged below the

ovary, the carpel occupies the central position and other floral parts are borne, below it in the irrespective whorls. e.g. China Rose

PERIGYNY:If the thalamus is flattened out to form a disc or a cup or flask shaped top, the remaining three whorls of flower and are inserted on the rimof the disc, and gynoecium will be placed on the top. e.g. Rose

2. EPIGYNY: In this type the thalamus is also a hollow cup or flask like structure but the ovary is completely fused with the inner wall of the thalamus. The gynoecium is described as inferior. Ex.Apple,Melon

PARTS OF FLOWER

1. CALYX: Outer most whorl of a flower is called calyx. It is non-essential whorl

and consists of sepals. Sepals may be free or fused.

2. COROLLA: It is present inner to calyx and consists of a number of petals which are brightly coloured to attract insects for pollination.

Shape of corolla: Cruciform , papilionaceous , tubular

Aestivation: Arrangement of floral parts on floral bud is known as Aestivation.

3. ANDROECIUM : It is the third and male whorl of the flower and is made up of one or more stamens.

Each stamen consists of filament and an anther.

4. GYNOECIUM: It is the female reproductive part of the flower and is made up of one or more carpels.A carpel consists of three parts namely stigma ,style and ovary.

LET US KNOW WHAT WE HAVE LEARNT!

PART: A VERY SHORT ANSWER TYPE QUESTIONS:

A. Multiple Choice Questions:

1.The study of external structure of organs is called......

a. Morphology

b. internal morphology

c. External morphology

d. Anatomy

2. If the thalamus is flattened out to form a disc or cup or flask:

a. Epigyny

b. Perigyny

c. Hypogyny

d. All of above

3. The stalk of the flower is called.

a. Style

b. Pedicel

c. Calyx

d. Petals

4. Which of the following is not a part of flower?

a. Pedicel

b. Seed

c. Stamen

d. Petal

5. Which part of flower attracts the insects.

a. Calyx

b. Corolla

c. Stamen

d. none of above

B. True /False:

a. The flower is a highly modified root which essentially for sexually

reproduction.

b. Perigyny is also a type of flower.

C. Fill in the Blanks:

(a). The flower is a modified

(b).The male reproductive part of flower is

ANSWERE KEY: PART-A

A. Multiple choice questions:

1. (c) external, means outside

2. (b) The shape gynoecium will be placed not on the top of the flower butin centre.

3. (b) which exposes the flower in favourable position for pollination

4. (b) because seed is a part of fruit, not a flower.

5. (a) itis the outermost whorl of flower,when becomes coloured or

produces nectar, attracts insects.

B. True or False:

(a) False: Flower is a highly modified shoot meant, which is

essential for reproduction.

(b) True: yes itis a type of flower, If the thalamus is flattened out to form a discor a cup or flask shaped top.

C. Fill Up:

a) Shoot

b) Stamen

PART: B SHORT ANSWER TYPE QUESTION:

1. Define the term flower also write its various parts.

2. Write different types of flower. Give their names with example.

3.Write short note on Perigyny with example.

4. What is inflorescence? Give its importance.

5. Give different parts of flowers. Name them with function.

PART: C LONG ANSWER TYPE QUESTION:

1. Draw a well labeled diagram of V.S. of a flower which shows different parts.

A56

INTRODUCTION:FLOWER is the reproductive unit in the angiosperms. Each flower normally has four floral whorls, viz., calyx, corolla, androecium and gynaecium.ws ds the female reproductive part of the flower and is made up of one or more carpels. A carpel consists of three parts namely stigma, style and ovary. Ovary is the enlarged basal part, on which lies the elongated tube, the style. The style connects the ovary to the stigma. The stigma is usually the tip of the style and the receptive surface for the pollen grains.Each ovary bears one or more ovules attached to a flatten cushion like placenta.

PLACENTATION: The arrangement of ovules within the ovary is known as

placentation. It is of following types:

1. 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. Marginal Placentation is found in monocarpellary pistils of

leguminosae e.g., Pea, Cassia, Acacia and other plants e.g., Larkspur

2. 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 false septum. E.g., Mustard and Argemone.

3. Axile Placentation: The placenta is axial and the ovules are attached to it in a multilocular ovary. E.g., China rose, Tomato, and Lemon.

4. Free Central Placentation: The placentation is called as free central when the ovules are born on central axis and the septa are absent. E.g., Dianthus and Primrose

5. Basal Placentation: The placenta develops at the base of ovary and

singel ovule is attached to it. E.g., Sunflower, Marigold

1. Flower is a:

(a.) Modified shoot for vegetative propagation

(b.) Modified shoot for sexual reproduction

(c.) Both (a.) & (b.)

(d.) None of the above

2. Gynaecium is:

a) Male reproductive organ of flower

b) Female reproductive organ of flower

c) For storage of food

d) None of the above

3. Monocarpellary type of ovary is found in:

a) Marginal Placentation

b) Axile Placentation

c) Parietal Placentation

d) None of the above

4. An example of axile placentation is:

a) Argemone

b) Marigold

c) Lemon

d) Dianthus

5. Sunflower shows:

a) Axile placentation

b) Free central Placentation

c) Basal Placentation

d) Marginal Placentation

b) FILLIN THE BLANKS:

1. is the receptive surface for pollen grains.

2. Ovules are attached to a flattened, cushion like

3. Dianthus shows type of placentation.

c) STATE TRUE OR FALSE

1. Ovary is not attached to the style and stigma.

2. False septum is formed in parietal placentation.

ANSWER KEY: PART-A

MULTIPLE CHOICE QUESTIONS

1. (b.) Modified shoot for sexual reproduction

2. (b.) Female reproductive organ of flower

3. (a.) Marginal Placentation

4. (c.) Lemon

5. (c.) Basal placentation

li - FILL IN THE BLANKS

1. Stigma- stigma is the receptive part of pistil that receives pollen

grains and help in the process of fertilization.

2. Placenta-it is the site inside the ovary where ovules are borne.

3. Free central-the ovules are borne around a central column and not

connected to ovary.

lil - STATE TRUE OR FALSE

1. False — Because ovary is the enlarged basal part on which the

elongated tube called as style lies. The style connects the ovary

to the stigma.

2. True

PART -B SHORT ANSWER TYPE QUESTIONS

1. Differentiate between Marginal Placentation and Parietal

Placentation.

2. Differentiate between Axile Placentation and Central Placentation.

3. Define Free Placentation and give its example.

PART-C LONG ANSWER TYPE QUESTIONS

1. Define Placentation and describe its various types with diagrams.

A57

INTRODUCTION:Dear students, today we will study about fruit and its types.FRUIT:- Fruit is a mature or ripened ovary , after fertilization.If a fruit is formed without fertilization of ovary it is called a parthenocarpic fruit .And such fruits are typically seedless.e.g. Banana.If a fruit is developed from other parts of flower as well as ovary is called false fruit e.g. Apple, Pear.

Structure of fruit _:-Generally the fruit consists of a wall or pericarp and seeds. The pericarp may be dry or fleshy. When pericarp is thick and fleshy it is differentiated into outer epicarp, the middle mesocarp and the inner endo carp.

Classifying Fruit : All fruits may be classified into three major groups on the basis of number of ovaries and the no of flowers involved in their formation :

A. Simple Fruits

B. Aggregate Fruits

C. Multiple Fruits

A. Simple Fruits:- Simple fruits develop from a single ovary of a single flower. These are of two types ,Dry fruits and Fleshy fruits

Dry Fruits: In dry fruits pericarp becomes dry at maturity.

These are of two types;- Dehiscent fruits, and Indehiscent fruits.

Dehiscent Fruits:-These fruits burst automatically and discharge seeds at maturity.

1.Follicle: composed of one carple and splitting along a single suture.

2.Legume: composed of one carpel and splitting along two sutures.

3. Capsule: composed of several carpels which separate at maturity in one or four ways.

4. Silique: Composed of two carpels which separate at maturity leaving a persistent partition between them.

Indehsiscent Fruits: These fruits do not split open at maturity

1.Achene: A one- seeded fruit with the seed attached to the fruit at one point only.

2.Caryopsis: A one- seeded fruit in which the seed is firmly attached to the fruit at all possible points.

3.Samara: A one or two- seeded fruit with the pericarp bearing a wing like out growth.

4.Schizocarp: Consisting of two carpels which at maturity separate along the midline into two one-seeded halves each of which is indehiscent.

5. Loment: Having several seeds, breaking into one- seeded segments at maturity.

6.Nut: A hard one-seeded fruit, generally formed from acompound ovary, with the pericarp hard throughout.Simple Fleshy Fruits: tn these fruits pericarp becomes fleshy at maturity.

1.Berry: Consisting of one or more carpels with one or more seeds, the ovary wall fleshy.

2.Drupe,a stone: Fruit is outer portion of pericarp derived from a single carpel and containing(usually) one seed.

3.Pome: It is derived from several carpels, receptacles and outer portion of fleshypericarp, inner portion of papery pericarp forming a core.

4. Hip: In this type of fruit several carpels are enclosed within the fleshy or semi fleshy receptacles.

B. Aggregate Fruit: These fruits consist of a number of ovaries formed in a single flower and are arranged over the surface of a single receptacle.Individual ovaries are called fruitlets.

C. Multiple Fruits: These fruits consist of the matured ovaries of

pineapple. Several to many flowers more or less united in a mass.

Accessory Fruits: Some fruits develop from tissues surrounding the ovary are called accessory fruits. These fruits can be simple, aggregate or multiple fruits. eg Apple and Fig.

Let us know what we have learnt!

Part: A_ Very Short Answer Type Questions:

Multiple choice questions:

1 A fruit that develops from single ovary of the single flower is called:

a) False fruit

b) Aggregate fruit

c) Simple Fruit

d) None of above

2 Example of parthenocarpic fruit is:

a) Apple

b) Banana

c) Mango

d) Coconut

3 Edible part in mango is:

a) Endocarp

b) Epicarp

c) Mesocarp

d) Both a and b

4 An aggregate fruit is one which develops from

a) Multicapellary syncarpous gynoecium

b) Multicapellary apocarpous gynoecium

c) Complete inflorescence

d) Multicarpellary superior ovary

5 Free nuclear endosperm is an edible part in:

a) Pineapple

b) Coconut

c) Botha andb

d) None of above

Fill in the blanks

1. ............. Seeds burst automatically and discharge seeds at maturity.

2. ............... fruit is composed of several carpels which separate at maturity in

one or four ways

3. In fleshy fruits................becomes fleshy at maturity.

True/ False

1. Accessory fruits develop from tissue surrounding the ovary.view

2. A true fruit develops from an unfertilized ovary.

Multiple choice questions

1. c (Aggregate and multiple fruits develop from more than one carpels of same

or different flowers)

2. b (Banana develops from unfertilized ovary)

3.c (IN mango epicarp and endocarp is not edible)

4.b (Simple fruit develops from single ovary and multiple fruit develops from several ovaries of many flowers)

5.b (there is no nuclear endosperm in pineapple)

Fill in the blanks:

1. Dehiscent

2. Capsule

3. Pericarp

True/ False:

1. True

2. False (True fruit develops from fertilized ovary)

Part: B Short Answer Type Questions:

1. What are multiple fruits?

2. Define schizocarpic fruit.

3. What are assesory fruits?

4. Give three examples of aggregate fruits.

Part: C Long Answer Type Questions:

1. Write an account of various types of fruits.

A58

INTRODUCTION:What is Seed?Seed is fertilised and ripened ovule ( mature integumented megasporangium) found in phanerogams. It contain an inactive embryo and reserve food for its future development.

A Seed has two parts namely seed coat and kernel. Seed coat is protective in natrure and derived from integuments of ovule which in turn derived from chalaza of ovule. A small pore called micropyle is found on seed coat for passage of water during germination. Kernel is represented by endosperm and embryo. Endosperm may not be present in all seeds; embryo has two ends embryo axis with plumule

(future shoot) and radicle (future root) on other end.

A Seed represents 3 generations:

1. Future sporophyte (embryo)

2. Parent sporophyte (seed coat)

3. Endosperm (female gametophyte — provide nutrients)

Seed Dormancy: It is innate inhibition of germination of an otherwise viable seed even when it is placed in most favorable external conditions.

Reasons of dormancy in Seeds:

1. Impermeable seed coats are impermeable to water e.g. Chenopodium

lequmes.

2. Inhibitors. Ferulic acid present in Tomato juice doesn't allow seeds to germinate.

3. Excess salts: Seeds of Atriplex has so much amount of salts.

4. Immature Embryo: In Gingko the embryo is immature at the time of seed shedding.

TYPES OF SEED:On basis of number of cotyledon, two broad categories of seeds as:

MONOCOT SEED:It is a type of seed with single cotyledon and the basic part of such seeds include:

Seed Coat: In seed of cereals like maize the seed coat is

generallymembranous and fused with fruit wall called Hull.

Endosperm. The endosperm is generally bulky and store food. Majority of monocotyledonous seed are endospermic but some as orchids are non-

endospermic.Aleuron layer. The outer covering of the endosperm separates the embryo by proteinous layer called aleuron layer.

Embryo. It is small and situated in the groove at one end of the endosperm.Scutellum. This is one large and shield shaped cotyledon.

Embryonal axis. Plumule at one end and radicle on another end.

Coleoptile and Coleorhiza. The plumule and radicle are enclosed in a

sheath called as coleoptile and coleorhiza respectively.

DICOT SEED:Seed with two identical cotyledons fall under the category of Dicot seeds and It includes following Seed coat. It is the outermost covering of the seed and further differentiated into outer testa and inner tegmen.Hilum. The hilum is a scar on the seed coat through which the developing seed was attached to the fruit.

Micropyle. It is small pore present above the hilum.Embryo. It consists of embryonal axis and two cotyledons.Cotyledons. These are often fleshy and full of reserve food material.

Radicle and Plumule. They are present on two ends of the embryonal

axis.Endosperm. In some seeds such as castor the endosperm is formed as a result of double fertilization,is a food storing tissue. In plants such as beans, gram and pea the endosperm is not present in the mature seed, they are known as non endospermous.

A. MULTIPLE CHOICE QUESTIONS:

Q1 The scientific study of seed is called as :

(a) Anthology

(b) Spermalogy

(d) Seedology

Q2 The aleuron layer in maize grain is rich in

(a) Lipids

(b) Proteins

(d) Starch

Q3 A Dicot seed with only one cotyledon is found in:

(a) Monotropa

(b) Abronia

(d) Cuscuta

Q4 Non albuminous seeds are found in:

(a)Maize

(b) Rice

(d) Valliseneria

Q5 Scutellum is a part of:

(a) Embryo

(b) Endosperm

(d) Pericarp

Q6 Epigeal germination occur in which among following:

(a) Cover

(b) Maize

(d) Castor

Q7 Micropyle of seed is involved in passage of:

(a) Male gametes

(b) Pollen tube

(d) Gases

Q8. Seed Dormancy is

(a) Innate inhibition.

(b) Internal inhibition of germination

(d) All above

B. FILL IN THE BLANKS:

1. Part of embryo that comes out first during seed germination........

2. Development of fruit without fertilization..............

3. Phenomenon in which seed germination occur while fruit still

attached to plant...........

4. In Sunflower........and...........are oily

C. TRUE/ FALSE:

1. Tigellum is another name for embryonal axis.

2. In Dicot seed, cotyledon is terminal and plumule is lateral.

3. A cotyledon in Jack fruit contains latex in them.

4. In pulses the proteins are stored in Endosperm.

5. In Hypogeal germination cotyledon become green and synthesis food.

A. MULTIPLE CHOICE QUESTIONS:

1. b Spermalogy is the scientific study of seeds.

2. c Aleuron layer in maize is richest source of Proteins.

3. b Abronia plant is the right option as it is Dicot seed with only one cotyledon.

4. d Vallisneria has non albuminous kind of seed.

5. a Scutellum is part of an embryo in the seed.

6. d Epigeal type of germination is characteristic feature of Castor plant

7. Micropyle in the seed is point for entry of water during germination.

8. Seed Dormancy is due to all above mentioned options

B. FILL IN THE BLANKS:

1. Radicle

2. Parthenogenesis

3. Vivipary

4.Embryo, Perisperm

C. TRUE /FALSE:

1. TRUE

2. FALSE In Dicot seed cotyledon is lateral and Plumule is terminal

3. TRUE

4. FALSE In pulses cotyledon is the site for storage of proteins not

endosperm.

5. FALSE In Epigeal germination cotyledon becomes green and

synthesize food.

Q1. Draw weil labelled diagram of V.S. of maize seed.

Q2. Differentiate between Epigeal germination and Hypogeal germination.

Q1. Enumerate difference between Monocotyledonous Seed and

Dicotyledonous Seed.

Q2. What is Seed Dromancy? List various reasons responsible of

dormancy in Seeds.

A59

INTRODUCTION:Dear students, today we will learn about important families of flowering plants (angiosperms).With respect to our syllabus and examination point of view there are three families, we will focus on: FABACEAE, SOLANACEAE & LILIACEAE.Each family will be discussed under three main sub headings:

Vegetative Characters,Floral Characters and Economic Importance.

FABACEAE The family was earlier called Papilionoideae, a sub family of family Leguminosae. It is distributed all over the world. It is commonly known as legume ,pea or bean family.

VEGETATIVE CHARACTERS:Trees, shrubs and herbs;

ROOT: Tap root system, nodulated roots bearing small nodules having

nitrogen fixing bacteria of genus Rhizobium(Rhizobium leguminosarum).

STEM: Erect or climber.

LEAVES: Alternate, simple(Crotalaria) or pinnately compound(Pisum

lathyrus), stipulate, reticulate venation.

FLORAL CHARACTERS:

INFLOROSCENCE: Racemose

FLOWER: Bisexual, zygomorphic.

CALYX: Sepals five, gamosapalous, imbricate aestivation.

COROLLA: Petals five,polypetalous, papillionaceous, 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, momo carpellary, unilocular with many ovules,single style.

FRUIT: Legume; seed: one to many, non endospermic.

ECONOMICAL IMPORTANCE:Many plants belonging to this family are sources of :

Pulses: Gram, arhar, sem, moong, soyabean);

Vegetable: Young green pods of various pulses and others( Vicia faba,

Lablab purpureus, Guar bean) Edible oil: Soyabean, groundnut;

Dye: Indigofera, red dye (Pterocarpus)

Fibres:sunhemp. Used for preparing ropes, nets ,canvas, mats etc.

Fodder: Sesbania, Trifolium.

Ornamentals: lupin, sweet pea.

Medicine: Mulaithi(Glycyrrhiza glabra) used for cough. Abrus precatorium (Ratti) used for leukoderma. Juice of Agast used fo improving eyesight.

Soil fertility: Members of family fabeceae improve soil fertility by nitrogen fixation.

SOLANACEAE It is a large family, commonly called as the ‘potato’ family. It is widely distributed in tropics, subtropics and even temperate zones.

VEGETATIVE FEATURES:Plants mostly herbs, shrubs and rarely small trees.

ROOT:Tap root

STEM: Herbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, underground stem in potato(Solanum tuberosum).

LEAVES: Alternate, simple, rarely pinnate compound exstipulate; venation reticulate.

FLORAL CHARACTERS:INFLORESCENCE: Solitary, axillary or cyamose as in Solanum FLOWER: Bracteate or ebracteate, Bisexual and actinomorphic.

CALYX: Sepals five,united, persistent, valvate aestivation, hairy, persistent,may enlarge in fruits.

COROLLA: Petals five, united, valvate aestivation

ANDROECIUM:Stamens five, epipetalous, polyandrous, anthers bithecous,

dehiscence by apical pores or longitudinal and inrorse, inferior.

GYNOECIUM: Bicarpellary,syncarpous;ovary superior, bilocular, placenta

swollen with many ovules.

FRUITS: Berry or capsule

SEEDS: Many, endospermous.

POLLINATION: Entomophilous. Visit flower for necter contained at base of ovary.

ECONOMICAL IMPORTANCE:

FOOD: Many plants of this family are used as food like Potato(Solanum

tuberosum) and tomato(Lycopersicum).

SPICES: Chilli(Capsicum annuum).

MEDICINE: Atropa belladonna yield atropine which is used as aantidote to poisons and in eye testing. Ashwagandha is also used in many medicines.

FUMIGATORY: Dried cured leaves and tender shoots of Nicotiana tobacum

yield tobacco. It is smoked, chewed or snuffed.

ORNAMENTALS: Important ornamentals are Petunia, Datura and Cestrum

nocturnum.

LILIACEAE Commonly called the ‘Lily family’ is a characteristic representative of monocotyladenous plants. It is distributed worldwide.

VEGETATIVE CHARACTERISTICS:Perennial herbs with underground bulbs, corms, rhizomes.

LEAVES: Mostly basal, alternate, linear, exstipulate with parallel

venation.

FLORAL CHARACTERS:INFLORESCENCE: Solitary/cymose, often umbellate clusters.

FLOWER: Bisexual; actinomorphic

PERIANTH: Tepal six(3+3), often united into tube; valvate aestivation.

ANDROECIUM: Stamen six(3+3)

GYNOECIUM:Tricarpellary, syncarpous, ovary superior,trilocular

with many ovules; axile placentation.

FRUIT:Capsule, rarely berry.

SEED: Endospermous.

ECONOMICAL IMPORTANCE:

FOOD: Bulbs of Allium cepa(onion) and Allium sativum(garlic) are used in cooking. Root tubers of Asparagus are used as vegetable.

MEDICINE: Aloin obtaines from aloe vera is used as purgative. Aloe vera is used for many skin problems and in cosmetics. Sarsaparilla obtained from roots of Smilax is a blood purifying drug. Colchicum is used in treatment of gout,rheumatism and liver ailments.

ORNAMENTALS: Important ornamentals are lily, tulips, Gloriosa.

PART A: VERY SHORT ANSWER TYPE QUESTIONS

A) MULTIPLE CHOICE QUESTIONS:

1. Flowers are actinomorphic in which of the following family?

a. Fabacea

b. Solanacea

c. Liliaceae

d. b and c.

2. Flowers are bisexual in which family?

a. Fabaceae

b. Solanacea

c. Liliaceae

d. All of above

3. Racemose inflorescence is found in which family?

a. Fabaceae

b. Solanaceae

c. Liliaceae

d. None

4. To which family does the following formula belongs to?

a. Solanaceae

b. Fabaceae

c. Liliaceae

d. None

5. Nitrogen fixing bacteria are found in plants of which family?

a. Liliaceae

b. Solanaceae

c. Fabaceae

d. All of above

B) FILL UPS:

a. Plants belonging to family are source of pulses.

b. Liliaceae is a characteristic representative of plants.

c. Tomato, potato, brinjal and chilli belong to family

C) TRUE OR FALSE:

a. Plants of family Solanaceae improve the fertility of soil.

b. Leaves of Allium cepa (onion) have parallel venation.

ANSWER KEY: PART-(A)

A) MULTIPLE CHOICE QUESTIONS:

ANSWER 1. d. ( Flowers in plants of fabaceae are zygomorphic.)

ANSWER 2. d. (All the three families have bisexual flowers. )

ANSWER 3. a. (Solanaceae and liliaceae has cymose inflorescence. )

ANSWER 4. a. (Plants of Solanaceae have pentamerous flowers which is

depicted in formula. In Fabaceae corolla possess vexillary aestivation which is not present in formula. Liliaceae is a trimerous family).

ANSWER 5. c. (Roots of plants in fabaceae family possess nodules for nitrogen fixation.)

B) FILL UPS:

a. Fabaceae

b. Monocotyledonous

c. Solanaceae

C) TRUE OR FALSE:

a. True

b. True

PART B: SHORT ANSWER TYPE QUESTIONS

1. What are important vegetative characters of family Fabaceae?

2. Write floral formula and floral diagram of family Solanacea?

3. Type of inflorescence found in plants of family Liliaceae?

4. Name and mention use of two medicinal plants of family Fabaceae.

PART C: LONG ANSWER TYPE QUESTIONS

1. Explain in detail economical importance of family Solanaceae.

A60

RECAPITULATION:Morphology is the science that deals with the study of form,size, colour, structure and relative position of various parts

of organisms. This chapter basically deals with morphology and modifications in parts of an angiospermic plant.Now let us do the NCERT book questions.

1. What is meant by modification of root? What type of modification of root is found in the:

(a) Banyan tree

(b) Turnip

ANS. Roots of some plants change their shape and structure and become modified to perform certain functions other than absorption and conduction of water and minerals. It is called modification of roots.

Roots are modified for support, storage of food and respiration, etc.

(a) Root modification in banyan tree : In banyan tree, the root modifies to form prop roots. Prop roots arise from branches and enter the soil. Thus, they provide mechanical support to densely branched, huge trees.

(b) Root modification in turnip : The modification of root found in turnip is napiform for food storage. The upper portion of these fleshy roots is inflated or swollen which tapers towards the lower end.

(c) Root modification in mangrove trees: In mangrove plants, i.e., plants growing in saline marshes, the branches of tap root come out of the ground and grow vertically upwards showing negative geotropism. These roots are called pneumatophores. They help to get oxygen for respiration.

2. Justify the following statements on the basis of external features:

(i) Underground parts of a plant are not always roots.

(ii) Flower is a modified shoot.

ANS. (i) Underground parts of plant are not always roots because sometimes the stem also becomes underground and gets modified into various forms to perform different functions of storage, vegetative propagation, perennation, etc.Underground modifications of stems are tuber, rhizome, corm and bulb. The underground stems can be distinguished from roots externally by the presence of nodes and internodes, axillary buds, scale leaves etc. and by absence of root cap and root hairs.

(ii) Flower is the reproductive part of the angiospermic plant and it is defined as the modified shoot because (a) like shoot, flower develops from an axillary or rarely terminal bud. (b) flowers may get modified into fleshy buds or bulbils, transition from foliage leaves to floral leaves is found in Paeonia. (d) Nymphaea shows transition from sepals to petals and petals to stamens, (e) In Passiflora and

Cleome long intemodes occur below gynoecium and stamens.

3.How is a pinnately compound leaf different from a palmately compound

leaf?

ANS. The compound leaves may be of two types, pinnately compound leaf and palmately compound leaf. In pinnately compound leaf, a number of leaflets are present on a common axis, the rachis, which represents the midrib of the leaf as in neem. Pinnately compound leaf may be of different types as unipinnate, bipinna te,tripinna te and decompound. In palmately compound leaf, the leaflets are attached at a common point, i.e., at the tip of petiole, as in silk cotton. Palmately compound leaf may be of different types as unifoliate, bifoliate, trifoliate, quadrifoliate and multifoliate.

4.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. In alternate type of phyllotaxy, a single leaf arises at each node in alternate manner, as in china rose,mustard and sunflower plants. 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.

5.Define the following terms:

(a) aestivation

(b) placentation

(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.

8.Describe modifications of stem with suitable examples.

ANS. Stems are modified to perform different functions. Underground stems of some plants are modified to store food in them. They also act as organs of perennation to tide over conditions unfavourable for growth. Different modifications of stem are :

(i) Underground modifications

(ii)Sub-aerial modifications

(iii)Aerial modifications

(i)Underground modifications of stem are discussed as follows:

(a)Tuber: It is the branch of main stem which accumulates or stores food in it and m swells up, e.g., Solarium tuberosum (potato).

(b) Rhizome: It is a branched, prostrate horizontally growing stem having nodes and internodes. On the nodes sessile scale leaves are formed, e.g., Carina,Zingiber officinale (ginger), Curcuma domestica (turmeric) etc.

(c) Corm: This is a spherical,branched, vertically growing thick underground stem with more diameter than length, e.g., Crocus sativus (saffron), Gladiolus, Colocasia esculenta (arvi) etc.

(d) Bulb: In bulb the stem is highly reduced and can be seen only as a disc-like structure bearing numerous fleshy scaly leaves, e.g., Allium cepa (onion), Allium sativum (garlic) etc.

(ii) Subaerial modifications : Sub aerial part of stem grows horizontally on the ground while some part remains underground. Vegetative propagation takes place by means of these. They may be of following kinds.

(a) Runner: It grows prostrate on the surface of soil. It develops at the base of erect shoot called crown. A number of runners arise from one erect shoot which spread in different directions. Each runner has one or more nodes which bear scale leaves and axillary buds, e.g., Cynodon (doob grass).

(b) Stolon: The nodes of horizontally growing underground stem give rise to branches which come out of the soil, e.g., Fragaria (strawberry).

(c) Sucker: Suckers are formed from the node of underground stem. Sucker comes up obliquely in the form of leafy shoot, e.g., Mentha (mint).

(d) Offset: Stem consists of thick and short intemodes. The branches are formed from the main stem and upper portion of each branch bears a group of leaves while the lower portion bears the roots. Each branch is capable of growing as an independent plant after separating from the parent plant, e.g., Eichhornia (water hyacinth), Pistia, etc.

(iii)Aerial modifications : The aerial portion of stem is modified to perform different functions, e.g., climbing, protection, food manufacturing, etc. It may show following types of modifications:

(a) Twinners : The stem is long, flexible and sensitive which can coil around an upright support like a rope, e.g., |pomoea, Convolvulus.

(b) Climbers : The stem is weak and flexible but is unable to coil around an upright support by itself. It requires the help of clasping or clinging structures. Accordingly,climbers are of four types : root climbers, e.g., Betel; tendril climber, e.g.,Passiflora; scramblers, e.g., Bougainvillea and lianas, e.g., Bauhinia.

(c) Phyliociade: The stem performs the function of photosynthesis. The stem modifies into green fleshy leaf-like structure having distinct nodes and intemodes. Leaves of such plants are reduced into spines in order to prevent loss of water, e.g., Opantia (prickly pear), Euphorbia.

(d) Cladode: It is similar to phylloclade with only one internode, e.g., Asparagus.

(e) Thorn: Stem is modified into stiff, pointed unbranched or branched structures which have lost their growing point and become hard, called as thorns, e.g.,Bougainvillea, Pomegranate, Citrus, etc. They perform defensive function.

(f) Tendrils : These are thread like sensitive structures which can coil around a support and help the plant in climbing, e.g., Cucurbita.

(g) Bulbils: In some plants vegetative buds or floral buds modify into a swollen structure called bulbil. It separates from the parent plant and on approach of favourable condition gives rise to a new plant, i.e., itis an organ of vegetative reproduction, e.g., Agave, Oxalis.

9. 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)

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, 2ygomorphic, 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, non- endospermic.

FAMILY SOLANACEAE (e.g., Solanum nigrum)

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.

10.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 is of different types namely, Marginal, Axile, Parietal, Basal & 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.

11.What is a flower? Describe the parts of a typical angiosperm flower.

ANS. Flower is the reproductive unit in the angiosperms. It is meant for sexual reproduction.A typical flower has four different kinds of whorls arranged successively on the swollen end of the stalk or pedicel, called thalamus or receptacle.These are CALYX, COROLLA, ANDROECIUM & GYNOECIUM.Calyx and Corolla are accessory organs, while Androecium and Gynoecium are reproductive organs.In some flowers like lily, the iE and are termed as Some flowers have both androecium and gynoecium and are termed hermaphrodite or Bisexual flowers while some flowers have only one of these two whorls, called as Unisexual flowers.

Calyx : The calyx is the outermost whorl of the flower and its units are called Generally, sepals are green, leaf like and protect the flower in the bud stage. The calyx may be gamosepalous (sepals united) or polysepalous (sepals free).

Corolla : Corolla is composed of [Ml Petals + are usually brightly coloured to attract insects for pollination. Like calyx, corolla may also be free (polypetalous) or united (gamopetalous). The shape and colour of corolla vary greatly in plants.Corolla may be tubular, bell-shaped, funnel-shaped or wheel-shaped.Androecium : Androecium is the a Itis composed of stamens. Each stamen which represents the male reproductive organ consists of a stalk or a filament and an anther. Each anther is usually bilobed and each lobe has two chambers, the pollen-sacs. The pollen grains are produced in pollen-sacs. A sterile stamen is called staminode.

Gynoecium : ies and is made up of one or more carpels. A carpel consists of three parts namely stigma, style and ovary. Ovary is the enlarged basal part, on which lies the elongated tube, the style. The style connects the ovary to the stigma. The stigma is usually at the tip of the style and is’ the receptive surface for pollen grains. Each ovary bears one or more ovules attached to a flattened, cushion-like placenta. When more than one carpel is present, they may be free (as in lotus and rose) and are called apocarpous. They are termed syncarpous when carpels are fused, as in mustard and tomato. After fertilisation, the ovules develop into seeds and the ovary matures into a fruit.

12. How do the various leaf modifications help plants?

ANS. Leaves perform various functions besides photosynthesis and thus they are modified into different forms such as —

(i)Leaf tendrils: The different parts of a leaf are modified into tendrils which help the plant in climbing up. Parts of leaf modified into tendrils include stipules e.g.,Smiiax ; petiole e.g., Clematis ; leaf apex e.g., Gloriosa ; leaflets e.g., Pisum; whole

leaf e.g., Lathyrus.

(ii)Leaf spines: Either for the protection of plant or to lessen the rate of transpiration in xerophytic plants, the leaves modify into sharp, pointed spines.Parts of leaf modified into leaf spines include stipules e.g., Zizyphus; leaf margins e.g., Argemone; leaf apex e.g.r Yucca; entire leaf e.g., Berberis.

(iii)Phyllode: Petioles modify into leafrlike green, photosynthesising structure e.g.,Parkinsonia, Acacia auriculiformis.

(iv)Scale or protective leaves : The leaves modify into hard scaly leaves which protect the vegetative bud by covering them, e.g., Ficus, Artocarpus, Casuarina,etc.

(v) Leaf hooks : They help in climbing e.g., Bignonia.

(vi)Leaf roots : A leaf transforms into roots for balancing on water e.g., Salvinia.(vii)Leaf pitchers : Leaf is modified into pitcher e.g., Nepenthes (insectivorous),Dischidia (non-insectivorous).

(viii)Leaf bladder: The leaves modify to form bladder like structure which trap insects and then it is closed by a valve present on the mouth of bladder e.g.,Utricularia (bladderwort).

(ix) Leaf tentacles: The leaf of sundew plant, Drosera bear minute hairs which have shinning, sticky substance at their tips (tentacles). When any insect sits on the leaf, it is covered by these hairs.

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

ANS. 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. The apex produces different kinds of floral appendages laterally at successive nodes instead of leaves. When a shoot tip transforms into a flower, it is

always solitary.Depending on whether the apex gets converted into a flower or continues to grow,two major types of inflorescence are defined - RACEMOSE and CYMOSE.

In RACEMOSE TYPE of inflorescence the main axis continues to grow, the flowers are borne laterally in acropetal succession.IN CYMOSE TYPE of inflorescence the main axis terminates in a flower, hence is limited in growth. The flowers are borne in a basipeta! order.

14. Write the floral formula of an actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens and two united carples with superior ovary and axile placentation.

ANS. The floral formula for actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens and two united carples with superior ovary and axile placentation is:

There is no symbol for axile placentation.

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

ANS. In a typical flower, the floral members like calyx, corolla, androecium and gynoecium are arranged over the thalamus.

Based on the position of calyx, corolla and androecium in respect to ovary on thalamus, the flowers are described as:Hypogynous, Perigynous & Epigynous ones.

In the 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, china rose and brinjal.In Pergynous flower, 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. The ovary here is said to be half inferior or sub superior, e.g., plum, rose, peach.In epigynous flowers, the margin of thalamus grows upward enclosing the ovary completely and gets fused with it. The other parts of flower arise above the ovary.

Hence, the ovary is said to be inferior as in flowers of guava and cucumber, and the ray florets of sunflower.

A61

RECAPITULATION:Dear students, today we will revise all important diagrams from chapter: 05 Morphology of flowering plants.

PARTS OF A FLOWERING PLANT:

1. Roots

2. Stem

3. Leaves

4. Flower

5. Fruit

6. Seed

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RECAPITULATION:DEAR Students as you have already done detailed discussion on the chapter MORPHOLOGY OF FLOWERING PLANTS and also discxussed the NCERT exercise questions.Now we will recapitulate differences type questions and also discuss about the sub topic:

FLOWER IS MODIFIED SHOOT.There are several evidences to support that flower is a modified shoot.

1. Flowers may develop in the axils of bracts like the axillary shoots.

2. In some plants the floral buds may sometime get modified into

vegetative buds or bulbils. e.g. Agave , onion

3. Paeonia shows gradual transition from vegetative leaves to floral

leaves.

4. The floral organs show all stages between a sepal and petal and

between a petal and stamen. E.g. Nymphaea (water lily)

5. Sepals are similar in morphology to leaves in Rose.

6. The growing point of thalamus may give rise to a shoot or another

flower above it.

7. The stamens of Degenaria are expanded like leaves.

8. The carpels of Degenaria appear like folded leaves. Style and stigma are not differentiated. -

9. Anatomy of pedicel and thalamus is similar to that of stem while

vascular supply to different floral organs resembles the vascular

supply for ordinary leaves.

PART-A

A.MCQs

1) The primary growth in root is due to

a) Zone of maturation

b) Zone of cell division

c) Zone of cell elongation

d) Meristematic region

2) Modified stem into green, flattened structure for assimilatory function is...

a) Phyllode

b) Phylloclade

c) Offset

d) Thom

3) The swollen end of the stalk of flower is called

a) Pedicel

b) Thalamus

c) Petiole

d) rachis

4) Edible part of coconut is

a) Epicarp

b) Endosperm

c) Mesocarp

d) Endocarp

5) Inferior ovary is present in

a) Hypogynous flower

b) Perigynous flower

c) Dichogamous flower

d) Epigynous flower

B. Fill in the blanks:

1. Pneumatophores bear small pores called............

2. .--------------- is edible part of ginger.

3. The arrangement of ovule in the ovary is called -----------.

C. True/ false:

1. Cymose in florescence shows limited growth.

2. The flower is highly modified root which is essential for

reproduction.

A.MCQ:

1. (d) Meristamatic region

2. (b) Phylloclade

3. (b) Thalamus

4. (b) Endosperm

5. (d) Epigynous

B. Fill in the blanks:

1. Lenticels

2. Rhizome

3. Placentation

C. True/False:

1. True

2. False- Flower is a modified shoot essential for reproduction.

PART -B

1. Differentiate between tap rootand adventitious root.

2. What do you mean by superior and inferior ovaries

3. List the various functions of root.

4. What is false fruit?

PART-C

1. Describe the various types of placentation found in flowering plants and represent diagrammatically.

2. What is flower? Describe the parts of typical angiospermic plants with the help of diagram.

A63

INTRODUCTION:Study of the internal structure of plants is called Anatomy. Plants have cells as the basic units. Cells are organised into tissues and in turn the tissues are organised into organs. Different organs in a plant show differences in their internal structure.Dear students, today we will study about Meristematic tissue which is a type of plant tissue.GE - A tissue is a group of cells having a common origin and usually

performing a common function.

A plant tissue is made up of different kinds of tissues. Tissues are classified into two main groups, namely Meristematic tissue and Permanent tissue based on whether the cells being formed are capable of dividing or not.

MERISTEMATIC TISSUE,A plant tissue that has the power to divide itself actively throughout its life is called a Meristematic Tissue. The term tissue is coined by C.nageli.

1. Meristematic tissue is a group of immature cells that has the power of continuous division.

2. Meristematic tissue is commonly called meristems.

3. Cells are tightly arranged i.e. intercellular space is absent.

4. They possess a single, large nucleus.

5. The Protoplasm of cells is very dense.

6. Vacuoles are normally absent, if present are small and few in number.

7. The meristematic tissue is living and thin walled.

8. They do not store food.

9. They exhibit a very high metabolic activity.

Types of Meristematic Tissue

Meristematic tissues can be classified on the basis of -

1. Based on origin

2. Based on position

Ome Seemed) Meristematic Tissue are of following types-

A. Promeristem

B. Primary Meristem

C. Secondary Meristem

A. Promeristemine earliest and youngest meristematic tissue.

It originates from the embryo.The primary meristem arises from the promeristem.It is found in the root and the shoot tips.

It arises from the promeristem.The primary meristem appears early in the life of a plant and is responsible for the development of the primary plant body.Primary meristem is present at the apical region of the plant body.

Example:- Shoot Apical Meristem, Root Apical Meristem

Develop later on in life.It is developed from primary meristem.

They are lateral in position like cork cambium, vascular cambium and

interfascicular cambium.

A. Apical meristem

B. Intercalary meristem

C. Lateral meristem

D. Apical Meristem

It is present at apical parts of plants such as root tip and shoot tip.If Apical meristem is present at root tip, it is called root apical meristem.

If present at shoot tip, it is called shoot apical meristem.

Cells remain active indefinitely.It helps to increase the height of plants.During the formation of leaves and elongation of stem, some cells ‘left behind’ from shoot apical meristem, constitute the axillary bud.

B. Intercalary Meristem It is found intercalated between permanent(mature) tissues above and below.Both apical meristem and intercalary meristems are primary meristems because they appear early in life of a plant.It is an actively growing region behind apical meristem.

It also adds to the height of plants.It is commonly present in grasses and regenerate parts removed by grazing herbivores.

It is present on the lateral side of stem and root.It helps in increasing the diameter or thickness of plants.It is thus responsible for secondary growth of plants.The lateral meristem divides and forms secondary permanent tissue.Example: vascular cambium (primary meristem) and cork cambium

(secondary meristem)

PART: AVERY SHORT ANSWER TYPE QUESTIONS:

A. Multiple choice questions:

1. Meristematic tissues are composed of:

a. mature cells

b. fully differentiated cells

c. cells that cannot divide

d. immature cells with power to divide

2. Vascular cambium and cork cambium are the examples of:

a. apical meristem

b. lateral meristem

c. intercalary meristem

d. promeristem

3. Which of the following is not a characteristic of meristematic cells:

a. Presence of intercellular spaces

b. Thin cellulosic cell walls

c. Presence of prominent nucleus

d. High metabolic rate

4. Which type of Meristematic tissue increases the diameter of plants:

a. shoot apical meristem

b. root apical meristem

c. lateral meristem

d. intercalary meristem

5. The shoot apical meristem is an example of:

a. primary meristem

b. secondary meristem

c. promeristem

d. both a and b

B. Fill up’s:

1. Both apical meristems and intercalary meristems are...........

meristems.

2. Regeneration of damaged growing grass is due to............... meristem.

C. True/False

1. Meristematic cells have dense cytoplasm and large nucleus.

2. Meristematic cells are mature and possess the ability to divide.

3. Primary meristems are developed early in plant life.

4. Meristematic cells are loosely arranged.

A. Multiple choice questions :

1. (d) Meristematic celis are composed of immature cells having the power of division

2. (b) Cork cambium and vascular cambium are examples of lateral meristems.

3. (a) Meristematic cells are compactly arranged i.e. intercellular spaces are absent.

4. (c) Lateral meristematic helps in increasing the diameter of plants.

5. (a) Both apical meristem and intercalary meristems are primary meristems because they appear early in life of a plant.

B. Fill up’s:

1. Primary

2. Intercalary meristem

C. True/False:

1. True; (Meristematic cells have dense cytoplasm and prominent nucleus as

they have to divide continuously.)

2. False: (the meristematic cells are immature and have the ability to

divide. )

3. True; (Primary meristems develop early in plant life wnereas secondary meristems develop late in plant life.)

4. False; (Meristematic cells are tightly arranged.)

PART: B SHORT ANSWER TYPE QUESTION:

1. Define Tissue. Name the various types of meristematic tissues.

2. What is an Intercalary Meristem?

3. What is the difference between Primary meristem and

Secondary meristem?

4. What's the main difference between Meristematic tissue and

Permanent tissue?

PART: C LONG ANSWER TYPE QUESTION:

1. Define meristematic tissue along with its characteristics & discuss various types of Meristematic tissues.

A64

INRODUCTION:TISSUES :- Tissues are groups of cells that have a similar structure and act together to perform a specific function.In plants, tissues are classified into two groups on the basis of cell

division capacity. These are:MERISTEMATIC & PERMANENT TISSUE.

Dear students, we have discussed about Meristematic Tissue in the

previous assignment.Today we will study about permanent tissues and there types.

A) MERISTEMATIC TISSUES:- These are a mass of undifferentiated cells

whose main function is to participate in plant growth. E.g. Root apex,

Shoot apex.

B) PERMANENT TISSUES:- These are differentiated tissues, carrying out

dedicated functions. Some of which is to render mechanical strength

to the plant, conduct or even to carry out photosynthesis. These

tissues are originated, differentiated and derived from meristematic.

E.g. Xylem, Phloem.

TYPES OF PERMANENT TISSUES:

Permanent tissues can be classified into two types. They are:

1) SIMPLE PERMANENT TISSUE

li) COMPLEX PERMANENT TISSUE

!) SIMPLE PERMANENT TISSUES:

These tissues are simple. They are made up only one type of cell. Here,all the cells that make up the tissue are similar and have the same structure, with the same type parts. Simple permanent tissues are again classified into three main types. They are parenchyma, collenchyma, and sclerenchyma.

A) PARENCHYMA - The cells of this tissue are living, with thin cell walls. Cells can be oval or round in shape. They have a large central vacuole and a dense cytoplasm. The parenchyma tissue is located in the soft parts of the plant such as cortex and pith. It mainly acts as a packing tissue, providing mechanical support. It also helps in the storage of food. Based on the specific functions, parenchyma can be further classified into Aerenchyma and Chlorenchyma.

a) COLLENCHYMA - These cells are living cells and have an elongated

shape. The comers of the cell wall are thickened.There is very little intercellular space present. The collenchyma tissue can be located in the leaf stalks, below the epidermis etc. Its main function is to provide flexibility to the plants as well as mechanical support.

B) SCLERENCHYMA - The cells of the sclerenchyma tissue are dead. The

cell wall is very thick due to the deposition of lignin. The cells of this tissue can be in different shapes and sizes. They are generally located in the leaf veins, hard coverings of the seeds and can also be found surrounding the vascular bundle. The main function of the sclerenchymatic tissue is to provide rigidity and mechanical support to the plant body. They also make the plant stiff and hard.

I) COMPLEX PERMANENT TISSUE The complex permanent tissues are made up of more than one type of cell.They coordinate together to perform the same specialized functions in the plant body. They are classified into two types - XYLEM & PHLOEM

A) XYLEM - The xylem tissue is responsible for the conduction of water and minerals from the roots to the leaves and stem. It also provides support to the plants. It has four elements. They are tracheids, vessels, xylem parenchyma and xylem fibres.

A) PHLOEM - This complex permanent tissue helps in the translocation

of food that is prepared by photosynthesis in the leaves to various

parts of the plant. Phloem consists of four elements.They are sieve tubes, companion cells, phloem fibres and phloem parenchyma.

LET US KNOW WHAT WE HAVE LEARNT!

PART: A - VERYSHORT ANSWER TYPE QUESTIONS

A)MULTIPLE CHOICE QUESTIONS:

1. Which tissue provides mechanical strength to plants?

a) Parenchyma

b) Xylem

c) Collenchymas

d) Phloem

2. The simple tissue consisting of living cells and provide

mechanical strength to plants is:

a) Sclerenchyma

b) Parenchyma

c) Chlorechymas

d) Collenchymas

3. The most common ground tissue in plant is:

a) Epidermis

b) Cortex

c) Parenchyma

d) Collenchymas

4. Most metabolism of the plants is carried in tissue:

a) Epidermis

b) Cortex

c) Parenchyma

d) Collenchymas

5. The tissue most abundant in Hydrilla/Eichhornia

a) Aerenchyma

b) Colenchyma

c) Phloem

d) Sclerenchyma

B) Fill ups;

1. Sugar transport elements of gymnosperms and pteridophytes

APE...

2. Plant regeneration can occur from mature parenchyma cells

because it can...

3. Internal plant organisation is studied under...........

C)True /false

1. Xylem and phloem belongs to group of complex tissues.

2. Vessels are absent in monocots and dicots.

3. Shoot is the first to die wnen xylem is removed.

ANSWER KEY: PART-A

A) MULTIPLE CHOICE QUESTION:

Ans 1. b (XYLEM) provides mechanical strength to plants.

Ans 2. d (COLLENCHY MAS) simple tissues consisting of living cells and

provide mechanical strength.

Ans 3. c(PARENCHYMA) most common ground tissue

And 4. d (COLLENCHY MAS) performs metabolism

Ans 5. a (AERENCHYMA) tissue most abundant in Hydrilla/Eichhornia

B) FILL UPs:

1. SIEVE CELLS

2. DEDIFFERENTIATE

3. ANATOMY

C) TRUE/FALSE:

1. TRUE

2. FALSE (VESSELS ARE PRESNT IN BOTH MONOCOTS AND

DICOTS)

3. TRUE

PART B: SHORT ANSWER TYPE QUESTIONS:

1. Differentiate between parenchyma and collenchymas.

2. Write a short note on Sclerenchyma tissues.

3. Discuss the importance of xylem in plants

4. Differentiate between Xylem and Phioem.

PART C: LONG ANSWER TYPEQUESTIONS:

1. Define permanent tissue of plants? Discuss its various types

in detail.

Chapter 5 Morphology Of Flowering Plants

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Friday 5 February 2021

Chapter 5 Morphology Of Flowering Plants

Chapter 5 Morphology Of Flowering Plants

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