1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants

Karnataka 1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants

1st PUC Biology Morphology of Flowering Plants One Marks Questions and Answers

Question 1.
What is pulvinus?
Answer:
The swollen leaf base is called pulvinus.
eg: F – Leguminosae.

Question 2.
Define morphology.
Answer:
Morphology is the branch of science or biology, that studies the external features of an organism.

Question 3.
What are adventitious roots?
Answer:
Adventitious roots are those roots which arise from any part of the plant, other than the radicle.

Question 4.
What is a leaf lamina?
Answer:
The lamina is the green expanded part of the leaf with veins and veinlets.

Question 5.
What is a bract?
Answer:
Bract is a reduced leaf-like structure found at the base of the pedicel of a flower.

Question 6.
What is a staminode?
Answer:
Staminode is a sterile stamen, that does not produce pollengrains.

Question 7.
What are parthenocarpic fruits?
Answer:
Parthenocarpic fruits are those fruits which develop without fertilisation of the ovary.

Question 8.
What is Zygomorphic flower?
Answer:
If the flower can be divided into two similar halves along one plane only, that flower is called Zygomorphic.

Question 9.
What is double fertilization?
Answer:
Fusion of one of the male gametes with the egg and the second male gamete with the secondary nucleus is called double fertilization.

Question 10.
What are aggregate fruits?
Answer:
These are the fruits developed from separate carpels belonging to a single flower.
Example : Magnolia.

Question 11.
What is bract?
Answer:
Bracts are modified leaves and usually flowers arise in their axils.

Question 12.
Define the following terms:
(a) aestivation
(b) placentation
(c) actinomorphic
(d) zygomorphic
(e) superior ovary
(f) perigynous flower
(g) epipetalous stamen.
Answer:
Refer:-
(a) The mode of arrangement of sepals, petals or even tepals in a flower bud is called aestivation.
(b) The mode of arrangement of placenta or placentae from which ovules are developed is called placentation.
(c) The mode of arrangement of placenta or placentae from which ovules are developed is called placentation.
(d) Actinomorphic – A flower that can be cut into two equal parts ín any plane.
(e) Zygomorphic – A flower that can be cut into two equal parts in only one plane.
(f) Epipetalous is a condition in which the stamens are attached to petals of the flowers instead of being inserted directly over the thalamus. For example, Solanum.

Question 13.
What are adventitious roots?
Answer:
Roots that arise from parts of the plants other than the radical, are adventitious roots.

Question 14.
Give the three regions of the root tip?
Answer:
Region of maturation, region of elongation and region of meristamatic activity.

Question 15.
What is a lateral flattened photosynthetic structure borne on the stem called?
Answer:
Leaf.

Question 16.
What are the three main parts of a leaf?
Answer:
Leaf base, petiole and lamina.

Question 17.
Define venation?
Answer:
Arrangement of veins and veinlets on the lamina of a leaf.

Question 18.
Name the venation seen in
(a) dicot leaf
(b) monocot leaf.
Answer:
(a) reticulate
(b) parallel.

Question 19.
What is inflorescence?
Answer:
The arrangement of flowers on the floral axis.

Question 20.
What type of floral succession is seen in
(a) racemose
(b) cymose.
Answer:
(a) acropetal
(b) basipetal.

Question 21.
Name the inflorescence where the main axis shows unlimited growth.
Answer:
Racemose

Question 22.
What is a perianth?
Answer:
When calyx and corolla of the flower are not distinct.

Question 23.
What is aestivation?
Answer:
The mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl.

Question 24.
What is staminode?
Answer:
A sterile stamen.

Question 25.
What is monoadelphous? Give an example.
Answer:
Stamens united into a single bundle is called as monoadelphous condition
eg: China rose.

Question 26.
What is diadelphous condition? Give an examples.
Answer:
Stamens united in two bunches is called as Diadelphous condition eg: Pea.

Question 27.
What is polyadelphous? Give an example.
Answer:
Stamens united in more than two bundles eg: Citrus.

Question 28.
Name the parts of carpel.
Answer:
Stigma, style and ovary.

Question 29.
What is apocarpous? Give an example.
Answer:
When more than one free carpel is present, eg: Lotus / Rose.

Question 30.
What is syncarpous? Give an example.
Answer:
When more than two carpels are present and if the carpels are fused, eg: Mustard / Tomato.

Question 31.
What is placentation?
Answer:
The arrangement of ovules within the ovary on a fertile tissue.

Question 32.
Name any four types of placentation.
Answer:
Marginal, Axile, Parietal, Basal, Central, Free central.

1st PUC Biology Morphology of Flowering Plants Two Marks Questions and Answers

Question 1.
What are nodes and internodes?
Answer:
Nodes are the regions on the stem where leaves arise. Intemodes are the regions on the stem between two nodes.

Question 2.
What is root cap? What is its function?
Answer:
Root cap is the cap-like structure that covers the root apex/tip. It protects the tender apex of the root as it penetrates through the soil.

Question 3.
What is a petiole? Mention the function of petiole.
Answer:
The stalk of the leaf is called petiole.
Functions:- It helps to hold the leaf blade to the light.
It also helps the blade to flutter in wind.

Question 4.
What is a seed? What are the two major parts of seed?
Answer:
A fertilised and mature ovule is called a seed. A seed has two parts.
(i) An embryonal axis.
(ii) One or two cotyledons.

Question 5.
What are trimerous flowers? Which group of plants has trimerous flowers?
Answer:
Trimerous flowers are those, where the flora appendages are in threes or multiples of three Morphology of Flowering pum
Monocotyledonous plants generally have trimerous flowers growing in marshy/swampy areas, where oxygen is deficient in the soil. These roots help the plants to get oxygen from the air for respiration.
eg: Rhizophora.

Question 6.
Differentaite between Hypogynous and Epigynous flowers.
Answer:
(i) In hypogynous flower, the thalamus is convex of flat and gynoecium occupies topmost position and other floral parts originate below.
In epigynous flowers, thalamus is cup shaped enclosing ovary and the floral parts will be arranged above it.
(ii) In hypogynous flower, ovary is superior in epigynous flowers, ovary is inferior.

Question 7.
What is a flower? Write the essential parts of a flower.
Answer:
A flower is a highly condensed shoot, specialized for sexual reproduction. Essential parts of a flower are androecium and gynoecium.

Question 8.
What is Placentation? List the types.
Answer:
Mode of arrangement of placenta is called placentation. Types of placentation are marginal, axile, parietal and basal.

Question 9.
With reference to fertilization explain :
(a) Triple fusion
(b) Double fertilization.
Answer:
Triple fusion : The fusion between haploid sperm with diploid secondary nucleus (endosperm nucleus) is called triple fusion.
Double fertilization : Participation of two sperms and their fusion, one with egg and another with secondry nucleus is called double fertilization.

Question 10.
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.
Answer:
(i) Underground parts of a plant are not always roots : In some plants stems remain underground to carry out some additional functions, like food storage and vegetative propagation. For example: Potatoes are modified form of underground stem.
(ii) Flower is a modified shoot: When the stem takes on the role of general reproduction it is modified into a flower. That is why flower is often called a modified shoot.

Question 15.
How is a pinnately compound leaf different from a palmately compound leaf?
Answer:
Pinnately compound leaves:
‘ Leaves in which leaflets are arranged laterally on the primary (main) rachis or its branches are called pinnately compound leaves. They are of the following types:

1. Unipinnate – leaves in which leaflets are directly borne on the primary rachis.
(a) Unipinnate and paripinnate – leaves with even number of leaflets.
e.g: Tamarindus, Cassia auriculata, Abrus etc.
(b) Unipinnate and imparipinnate – leaves with odd number of leaflets.
e.g: Rose, neem, indigofera, tephrosia etc.

2. Bipinnate – leaves in which leaflets are borne on the lateral (secondary) rachis of the primary (main) rachis. E.g. Acacia arabica
3. Trlpinnate – leaves in which the leaflets are borne on the tertiary rachis. e.g: Moringa indica

Palmately compound leaves:
Leaves in which either a single leaflet or more leaflets are borne at the tip of the rachis are
called pabnately compound leaves. They are of the following types:
1. Unifoliate – with a single leaflet. e.g: Citrus species (Lemon, orange).
2. Bifoliate – with two leaflets. e.g: Balanites.
3. Tnfoliate – with three leaflets. e.g: Oxalis.
4. Tetrafoliate – with four leaflets. e.g: Clarkia, marsilea (a pteridophyte).
5. Multifoliate – with five or more leaflets. e.g: Bombax.

Question 16.
Differentiate between:
(a) Racemose and cymose inflorescence.
(b) Fibrous root and adventitious root.
(c) Apocarpous and syncarpous ovary.
Answer:
(a) Racemose or indefinite inflorescence :

Inflorescences in which the peduncle or its branches do not terminate in a flower, but continue to grow and develop new flower buds are known as racemose inflorescence.
The opening of flowers is either acropetal or centripetal.

Cymose or definite inflorescences

Inflorescences in which the main peduncie and its successive lateral branches terminate in a flower are called cymose inflorescences.
The opening of flowers is either basipetal or centrifugal.

(b) 1. Fibrous root system – an adventitious root system consisting of fibre-like roots. e.g. Grasses.
2. Adventitious-root system – a root system developed from any part of the plant except the radicle.
e.g. Maize, jowar, etc.

(c) Apocarpous ovary
1. The flowers with apocarpus ovary have more than one carpel. These carpels are free.
2. It forms an aggregate of fruits
3. Apocarpous condition seen in Ranunculus,Aconitum, etc.

Syncarpous ovary
1. The flowers with syncarpous ovary have more than one carpel. However, these carpels are fused.
2. It forms only one fruit with one or many seeds
Eg: flowers of tomato and mustard.

1st PUC Biology Morphology of Flowering Plants Three Marks Questions and Answers

Question 1.
Explain with suitable examples, the different types of phyllotaxy.
Answer:
Phyllotaxy:
The mode of arrangement of leaves on the stem axis is known as phyllotaxy. The different
kinds of phyllotaxy are as follows:

1. Alternate – arrangement of leaves alternatively only one at each node with all the leaves usually in a single vertical plane.
e.g. Anona squamosa (custard apple), Polyalthia, etc.

2. Opposite – arrangement of two opposite leaves at each node.
(a) Opposite superposed – successive pairs of leaves just above the preceding pair. As a result of all the pairs of leaves are in a single plane. e.g. Quis quails indica.

Question 2.
Draw the labelled diagram of the following:
(i) gram seed
(ii) V.S. of maize seed
Answer:
(i) Bean seed is an exalbuminous seed or non endospermic seed, It is kidney shaped. It contains seed coat and embryo.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.3

Seed Coat: It is the outer protective covering of the seed which is brownish red in colour. It differentiated into two layers namely, outer testa and inner tegmen. Testa is hard, brownish raol layer developed from outer integument of the ovule. It is provided with a white ridge called raphe and a broad scar called hilum. Micropyle is present as a small pore near the hilum. Tegmen is the thin white membranous layer which encloses the embryo.

Embryo: It consists of enibtyonal axis and a pair of fleshy cotyledons. The pointed end of the axis is called radicle and the leafy end of the axis lying between the two cotyledons is called plumule. The part of embryonal axis present just above the attachment of cotyledons is called epicotyl and part of the axis below the attachment is called hypocotyl

2. StructuraI of a typical Monocotyledonous seed:
e.g: Maize grain.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.4

Maize grain is one seeded dry dehiscent fruit called caryopsis. It is an example for albuminous or endospermic seed. It has a flat, oblong, coloured body and consists of a grain wall called hull, endosperm and embryo.

Grain wall: It is outer protective covering of the seed. It is yellow in colour. It consists of fruit wall (pericarp) and seed coat. These two layers are firmly attached and not separable from one another.

Endosperm: It forms the major ‘bulk of the grain’ (2/3). It is composed of endospermal cells containing starch. It is externally bounded by a layer of cells called aleurone layer which contains mainly protein. Endosperm is separated from embryo by a layer of cells called epithelium.

Embryo: It occupies a small area of the grain on one side of the base. It consists of a single shield shaped cotyledon called scutellum and embryonic axis. Embryonic axis consists of pointed ends called radicle and plumule. Radicle is protected by a sheath called coleorhiza and plumule is by a sheath called coLeoptile. At the time of germination, radicle develops into the root system and plumule into the shoot system.

1st PUC Biology Morphology of Flowering Plants Five Marks Questions and Answers

Question 1.
Mention the characteristics of root system. Add a note on its function.
Answer:
Characteristics of root system:-
1. Root is underground and positively geotropic or negatively phototropic.
2. Root is non-chlorophyllous and brown in colour.
3. Root is not differentiated into nodes and intemodes.
4. Lateral roots are formed endogenously.
5. Root does not bear leaves and true buds.
6. Root apex is protected by a root cap.
7. Root bears unicellular root hairs.

Basic functions of the root:
1. The root system provides fixation or anchorage for the plant, into the soil.
2. Absorption of water and mineral ions from the soil is carried out by the root.
3. The root conducts the absorbed water and mineral salts from the root hairs to the rest of the plant body. This function is performed through cortex, endodermis and xylem.
4. Food materials are stored in the roots of many plants. This is done in the parenchyma cells of the cortex.

Question 2.
Define root. Write briefly the types of root system.
Answer:
The root is usually an underground part of the plant which helps in fixation and absorption of water. The radicle of the embryo develops into a primary root or tap root. Types of Root system:
The root system is generally of two types. They are,
1. Tap root system and
2. Adlventitious root system.

1. Tap root system:
The tap root system develops from the radicle of the germinating seed. It is also called the normal root system. The radicle develops into a primary root which grows vertically downwards and becomes the tap root. The tap root is the true root. It produces many lateral roots in an acropetal manna, endogenously which grow obliquely. The tap root system is present in dicotyledonous plants.

2. Adventitious root system:
The root system that develops from, any part of the plant body other than the radicle is called the adventious root system. It is mostly seen in monocotyledonous plants. In grasses, fibrous root system is present, which is a type of adventitious root system. In this case ‘the primary root formed from the radicle disppears soon. Then many slender roots develop from the base of the stone as cluster of fibres, hence called the fibrous robot system.

Question 3.
Describe the various types of placentations found in flowering plants.
Answer:
The mode of arrangement of placenta or placentae from which ovules are developed is called placentation. The different types of placentation are as follows:

1. Marginal – A single placenta located marginally.
eg: Pea, bean, groundnut, etc.

2. Basal – When the placenta is located on the flóor of the locule òf the ovary.
e.g: Tridax, Helianthus (Sunflower) etc.

3. Axle – When placentae are located along the axis of the ovary, but partitioned by radial septae.
e.g: Hibiscus, Tribulus, Allium cepa (onion), etc.

4. Free-central – When placentae are located along the axis of the ovary as n axile placentation, but are not partitioned by radial septae.
e.g: Dianthus

5. Parietal – When two or more placentae are longitudinally located on the inner side of ovary wall.
e.g: Cucurbita, Cucumis, Raphanus (radish), Brassica (mustard), etc.

Question 4.
What is a flower? Describe the parts of a typical angiosperm flower.
Answer:
Flower:
Flower is a modfed shoot ment for sexual reproduction in phanerogams.
Nelumba nucifera (Nelunilnum ,cpeciosurit) commonly known as sacred lotus, is the National flower of India.

However, the flowers are present only in angiosperms.
The flower of Rafflesia is the largest flower.
The flower of Wolffia microscopa is the smallest flower.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.2

A typical flower consists of following parts:-
1. Bract – A foliaceous or scaly or variously modified structure in the axil of which the flower is developed. Such a flower with a bract, is called bracteate flower. A flower without a bract is known as ebracteate flower.

2. Pedicel – The stalk of the flower. A flower with a pedicel is called pedicellate, while one lacking the pedicel is called epedicellate.
Lotus is a sessile flower.

3. Thalamus – The condensed floral axis on which the floral whorls are developed is called a thalamus. It may be conical, disc-shaped or cup-shaped. In certain plants, the floral axis may be elongated and differentiated into nodes and internodes.

4. Floral whorls: A typical flower possesses the following four whorls:-
(a) Calyx – Outermost whorl composed of sepals.
(b) Corolla – The second whorl composed of petals.
(c) Androecium – The third whorl composed of stamens.
(d) Gynoecium – The innermost and central whorl composed of one or more carpels. Of the four whorls, calyx and corolla are called accessory whorls, while androecium and gynoecium are called essential whorls.

Question 5.
Define the term inflorescence. Explain the basis for the different types inflorescence in flowering plants.
Answer:
The Inflorescence:

Inflorescence (L., inflorescere – to begin to blossom) is a specialized branch of the plant body which develops a single or group (s) of flowers.
The axis of the inflorescence on which the flowers are developed is called peduncle or rachis.
A modified peduncle ¡s known as receptacle.

Kinds of Inflorescence :

Inflorescences are basically grouped into three major types, namely racemose, cymose and special types.
Racemose or indefinite inflorescence :
inflorescences in which the peduncle or its branches do not terminate in a flower, but continue
to grow and develop new flower buds are known as racemose inflorescence.
The opening of flowers is either acropetal or centripetal.

Cymose or definite inflorescences:

Inflorescences in which the main peduncle and its successive lateral branches terminate in a flower are called cymose inflorescences.
The opening of flowers is either basipetal or centrifugal.

Specia inflorescences :
Inflorescences in which the peduncle is either completely reduced or variously modified and the opening of flowers is variable are called special inflorescences.

1st PUC Biology Morphology of Flowering Plants Text Book Questions and Answers

Morphology is the study of external form, structure and relative position of different organs. Parts of a Flowering Plant :
A flowering plant has a central plant axis having two components, underground and above-ground. The underground part of the plant axis is called the root system. The above-ground or aerial part is called the shoot system. Root system contains only roots and their branches. Shoot system consists of stem and its branches, leaves, flowers and fruits.

1. The Root:

The descending axis of the plant body is called root. It usually develops from the radicle of the embryo. .
A branched system of roots and rootlets is known as the root system.
Angiosperms exhibit three kinds of root systems which are as follows:

1. Tap-root system – a root system developed by the direct elongation of the radicle and its subsequent branching.
e.g. Bean, pea, mustard, castor, etc.
2. Adventitious-root system – a root system developed from any part of the plant except the radicle, e.g. Maize, jowar, etc.
3. Fibrous roof system – an adventitious root system consisting of fibre-like roots, e.g. Grasses.

A. Characteristics of roots:-
1. Roots are usually positively hydrotropic and geotropic. Hence they are usually underground. However, they are negatively phototropnic.
2. Unlike stem, they are not differentiated into nodes and intemodes.
3. They are devoid of leaves and buds.
4. They are also devoid of chloroplasts. Hence, they are usually non-green.
5. Young roots exhibit unicellular outgrowths called root hairs which enlwsnee Use area of absorption of water and minerals.

B. Functions of roots:
Roots normally perform the following two primary functions:-
1. Anchorage i.e., fixation of the plant, firmly in the soil.
2. Absorption of water and minerals and their conduction to the shoot system.
In addition to these normal functions, in some plants roots may be variously modified to carry out specialized functions called secondary functions which are as follows:
1. Storage of food materials.
2. Mechanical support.
3. Gaseous exchange or breathing.
4. Absorption of nutrients from the host plants.
5. Photosynthesis.
6. Absorption of atmospheric moisture.

C. Regions of young roots
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.1

A young root is differentiated into the following four regions:-
1. Apical meristem – the growing meristematic apex exhibiting mitotic activity. Hence, it is responsible for the addition of new cells. However, the extreme apex is mitotically less active and is known as quiescent centre.

2. Region of elongation – region of the root located just behind the apical meristem. It exhibits elongation of cells in addition to little mitotic activity. Hence, it is responsible for the elongation of root.

3. Region of root-hairs – region of the root which is just behind the region of elongation. It exhibits the differentiation of root-hairs from epidermal cells. Hence, it is concerned with absorption of water and minerals.

4. Region of maturation – that region which lies behind the root-hairs region. It exhibits the maturation of different permanent tissues including the vascular tissues. It may be noted that the lateral roots are formed in this region from the pericycle.

D. Root-caps and root-pockets:
The cup-shaped or cap-like structure which protects the apical meristem is known as root-cap.
Note: Pandanus (screw-pine) exhibits multiple root-caps.
The conical hollow structure that covers the apical meristem in free-floating hydrophytes
such as Eichhomia. Pistia, Lemna etc., is known as root-pocket.

II. The Stem:

The ascending axis of the plant body is called shoot. It is usually developed from the plumule of the embryo.
A branched or unbranched system of stems with leaves and buds is known as shoot system.
The axis of the shoot or that of a branch which bears leaves is called stem.

III. Leaf:

The lateral and usually flattened organs of the stem developed from the meristematic primordia of shoot (stem) apex are called leaves.
Ontogenetically, they are exogenous organs.
Positionally, they are located at the nodes.

A. Parts of a typical leaf
A typical leaf consists of the following three parts:
1. Leaf base (hypopodium) – that part of the leaf by which the leaf is attached to the stem.
2. Petiole (mesopodium) – the stalk of the leaf which acts as a connecting link between leaf base and lamina, also known as leaf blade.
3. Lamina (epipodium) – the broad or narrow flattened terminal part of the leaf. It is characterized by a system of veins and veinlets called venation.
Note: The three parts of the leaf mentioned above are collectively known as
phyllo podium.

B. Typical dicot and monocot leaves:

A typical dicot leaf consists of leaf base with a pair of free-lateral stipules, an elongated stalk
i. e., petiole and lamina with characteristic reticulate venation. e.g. Hibiscus (China rose).
A typical monocot leaf is differentiated into a sheathing leaf base and an elongated leaf blade with characteristic parallel venation, e.g. Zea mays (maize).
Note: Except in a few species, most of the monocots lack distinct petiole and stipules.

C. Venation of leaves:
The mode of arrangement of veins and veinlets is called venation. The two types of venation and their subtypes are as follows:-

1. Reticulate – when the venation appears in the form of reticulum i.e., net.
(a) Unicostate or pinnately reticulate – when there is a single mid-vein and lateral veins are developed from it. e.g. Ficus religosa, mango, etc.

(b) Multicostate or paimately reticulate – when two or more prominent main veins originate from the base of leaf lamina. e.g. Cucurbita. Coccinia, etc.

Multicostate divergent – when the main veins diverge rather than meeting at the tip of leaf lamina. e,g. Cucurbita, Coccinia, etc.
Multicostate convergent – when the main veins converge at the tip of leaf lamina. e.g. Cinnamomum.

2. Parallel- when the venation does not appear reticulate and the veinlets are parallely arranged.
(a) Unicostate or pinnately parallel – when there is a single mid-vein and lateral veins are developed from it. e.g. Canna indica, banana.

(b) Multicostate or palmately parallel – when two or more prominent main veins originate from the base of the leaf lamina. e.g. Gloriosa superba, grasses, palm leaflets

Multicostate divergent – when the main veins diverge rather than meeting at the tip of lamina. e.g. Grass leaf blade.
Multicostate convergent – when the main veins converge at the tip of leaf blade, e.g. Gloriosa superba.

D. Phyllotaxy:
The mode of arrangement of leaves on the stem axis is known as phyllotaxy. The different kinds of phyllotaxy are as follows:
1. Alternate – arrangement of leaves alternatively only one at each node with all the leaves usually in a single vertical plane.
e.g. Anona squamosa (custard apple), Polyalthia, etc.

Kinds of leaves:
Leaves are basically of two kinds, simple and compound.
Leaves with a single lamina or leaf blade, but lacking a joint between petiole and lamina are called simple leaves.

* On the other hand, leaves with one or more leaflets usually with a distinct joint between petiole (rachis) leaflets (s) are called compound leaves. The different kinds of compound leaves are as follows:

Pinnately compound leaves:

• Leaves in which leaflets are arranged laterally on the primary (main) rachis or its branches are called pinnately compound leaves. They are of the following types:
1. Unipinnate – leaves in which leaflets are directly borne on the primary rachis.
(a) Unipinnate and paripinnate – leaves with even number of leaflets. e.g: Tamarindus, Cassia auriculata, Abrus etc.
(b) Unipinnate and imparipinnate – leaves with odd number of leaflets. e.g: Rose, neem, indigofera, tephrosia etc.

2. Bipinnate – leaves in which leaflets are borne on the lateral (secondary) rachis of the primary (main) rachis. E.g. Acacia arabica

3. Tripinnate – leaves in which the leaflets are borne on the tertiary rachis. e.g: Moringa indica

Palmately compound leaves:
Leaves in which either a single leaflet or more leaflets are borne at the tip of the rachis are called palmately compound leaves. They are of the following types:-
1. Unifoliate – with a single leaflet.
e.g: Citrus species (Lemon, orange).
2. Bifoliate – with two leaflets. e.g: Balanites.
3. Trifoliate – with three leaflets. e.g: Oxalis.
4. Tetrafoliate – with four leaflets. e.g: Clarkia, marsilea (a pteridophyte).
5. Multifoliate – with five or more leaflets. e.g: Bombax.

G Functions of leaves:
The primary functions of leaves are:
1. Photosynthesis
2. Transpiration
3. Gaseous exchange to facilitate cellular respiration.

The Inflorescence:

Inflorescence (L., inflorescere – to begin to blossom) is a specialized branch of the plant body which develops a single or group (s) of flowers.
The axis of the inflorescence on which the flowers are developed is called peduncle or rachis.
A modified peduncle is known as receptacle.

Kinds of Inflorescence :
Inflorescences are basically grouped into three major types, namely racemose, cymose and special types.

Racemose or indefinite inflorescence :

Inflorescences in which the peduncle or its branches do not terminate in a flower, but continue to grow and develop new flower buds are known as racemose inflorescence.
The opening of flowers is either acropetal or centripetal.

Cymose or definite inflorescences

Inflorescences in which the main peduncle and its successive lateral branches terminate in a flower are called cymose inflorescences.
The opening of flowers is either basipetal or centrifugal.

Special inflorescences
Inflorescences in which the peduncle is either completely reduced or variously modified and the opening of flowers is variable are called special inflorescences.

III. Flowers:
Flower is a modified shoot meant for sexual reproduction in phanerogams.
Neiumba nucifera (Nelumbium speciosum) commonly known as sacred lotus, is the National flower of India.
However, the flowers are present only in angiosperms.
The flower of Rafflesia is the largest flower.
The flower of Wolffia microscopa is the smallest flower.

2. Pedicel – The stalk of the flower. A flower with a pedicel is called pedicellate, while one lacking the pedicel is called epedicellate.
Lotus is a sessile flower.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.2
3. Thalamus – The condensed floral axis on which the floral whorls are developed is called a thalamus. It may be conical, disc-shaped or cup-shaped. In certain plants, the floral axis may be elongated and differentiated into nodes and internodes.

A. echnical terms employed in the description of flowers.
1. Position of flower:
(a) Axillary – When a flower is developed in the axil of a leaf.
(b) Terminal – When the flower is developed at the tip of a branch.

2. Presence or absence of bract:
(a) Bracteate – When the flower has a bract of leaf at its base.
(b) Ebracteate – When the flower does not possess a bract.

3. Presence or absence of bracteoles:
(a) Bracteolate – When the flower has bracteoles.
(b) Ebracteolate – When the flower does not possess bracteoles.

4. Symmetry of Flower:
(a) Actinomorphic – A flower that can be cut into two equal parts in any plane.
(b) Zygomorphic – A flower that can be cut into two equal parts in only one plane.
(c) Asymmetric – A flower that cannot be cut into two equal parts in any plane.

5. Number of floral whorls:
(a) Complete – a flower possessing all the four whorls.
(b) Incomplete – a flower lacking any one or more whorls.

6. Dichlamydeous or monochlamydeous:
(a) Dichlamydeous – a flower possessing both calyx and corolla.
(b) Monochlamydeous – a flower lacking either calyx or corolla.

7. Bisexual or unisexual:
(a) Bisexual – a flower possessing both androecium and gynoecium.
(b) Unisexual – a flower possessing either only androecium or gynoecium.
(i) Unisexual staminate – possessing only androecium.
(ii) Unisexual pistillate – possessing only gynoecium.

8. Position of ovary:
(a) Hypogynous – a flower possessing superior ovary.
(b) Epigynous – a flower possessing inferior ovary.
(c) Perigynous – a flower possessing half-inferior and half-superior ovary.

9. Number of members in each whorl:
(a) Petamerous – each whorl, especially calyx and corolla possessing 5 members.
(b) Tetramerous – each whorl, especially calyx and corolla possessing 4 members.
(c) Trimerous – each whorl, especially calyx and corolla possessing 3 members.

B. Kinds of bracts:
A structure of variable shapes and colours located at the base of a flower or inflorescence is
called bract.

Parts Of Flower:
Each flower normally has four floral whorls namely calyx, corolla, androecium and gynoecium.

A.Calyx:
The outermost or the first accessory whorl of flower consisting of sepals is called calyx. However, in Hibiscus, a whorl of bracteoles form an additional accessory whorl lying below the calyx. It is known as epicalyx.
Some technical terms concerned with calyx:-
1. Polysepalous calyx – calyx with free sepals.
2. Gamosepalous calyx – calyx with fused sepals.

B. Corolla:
The second whorl of a flower consisting of petals is called corolla.
1. Polypetalous corolla – corolla with free petals.
2. Gamopetalous corolla – corolla with fused petals.
(a) Cruciform corolla – a polypetalous corolla with four free petals arranged in the form of cross. e.g: Radish, mustard, etc.
(b) Papilionaceous corolla – polypetalous corolla with a large standard petal called Vexillum, two wing petals called alae and two keel petals called carina. e.g: Pea, bean and other members of sub-family Papilionoidae (Papilionaceac)
(c) Tubular corolla – a gamopetalous corolla which is tubular.
e.g. Disk- florets of Family Asteracea (Compositae).

Aestivation of calyx and corolla:

The mode of arrangement of sepals, petals or even tepals in a flower bud is called aestivation. The different kinds of aestivation are as follows:-
1. Valvate aestivation – When sepals, petals or tepals are not overlapping.

2. Imbricate aestivation – When out of the total number of sepals, petals or tepals, one is completely out, one is completely in and the rest are in and out.

3. Descending imbricate aestivation – When the standard petals are large and overlap the two wing petals, which in turn overlap the keel petals. It is technically known as vexillary aestivation.
Note: It is characteristic of the members of sub family Papilionoideae (Papilionaceae). e.g: Pea, Bean, Indigofera, Tephrosia etc.

4. Ascending imbricate aestivation – When the small standard petal is completely in and is overlapped by the lateral wing petals which in turn are overlapped, by the keel petals. Note: It is characteristic of sub-family Caesalpinioideae (Caesalpinae).
e.g: Caesalpinia pulcherhima, Delonix regia, etc.

5. Quincuncial aestivation – When out of the total number of sepals or petals, two are completely out, two are completely in and the rest are in and out.

6. Contorted or twisted aestivation – When all sepals or petals are both in and out.

C. Androe Cium:

The third whorl of the flower or the first essential whorl of the flower composed of stamens is called androecium. A sterile stamen is called staminode.
A typical stamen consists of a stalk called filament, a connective and an anther.
While the connective links the two anther lobes, anther produces the pollen.
The stamens of an androecium may be free to exhibit cohesion or adhesion.

1. Cohesion of stamens – When stamens are partially or completely fused among themselves, the condition is known as adelphy. The types of adelphy may be any one of the following: ‘

(a) Monadelphous androecium – When all the stamens in a flower are fused by their filaments either partially or completely. e.g: Hibiscus, Abutilon, Crotalaria etc.

(b) Diadelphous androecium – When the stamens are fused by their filaments to form two distinct bundles either of (5) + (5) or (9) + (1).
e.g. Pisum (pea), Indigofera, Tephrosia, Clitoria, etc.

(c) Polyadelphous androedum – When the stamens are fused by their filaments to forms many bundles. e.g. Citrus (lemon, orange), Bombax, etc.

2. Syngenesious androedum – When stamens are fused by anthers, but filaments are free as in the members of Family Asteraceae (Compositae). e.g: Tridax, Helianthus (sunflower) etc.

3. Synandrous androedum – When both filaments and anthers are united to form one bundle, the stamens are said to be Synandrs. eg: Cycesrbita maxima.

4. Adhesion of stamens – When stamens are fused with other flower parts, it is called as Adhesion, it is of 2 types:-
(i) Epietaly : When the filaments of stamens are attached or fused with the petals. e.g: Datura, Hibiscus.
(ii) Epiphylly : Here stamens are attached to the perianth, eg: Lillium.

D. Gynoecium:
The fourth whorl of the flower or the second essential whorl composed of one or more carpels is called gynoecium or pistil and the female Reproductive part of the flower.

A sterile pistil is called pistillode. A typical gynoecium (pistil) is differentiated into a basal ovule(s) containing a part called ovary, a middle either elongated or short style and the pollen receiving terminal structure called stigma.

The position of ovary may be superior, inferior or half-inferior and half-superior as in hypogynous, epigynous and perigynous flowers, respectively.-

A gynoecium with free carpels is known as apocarpous, while one with fused carpels is known as syncarpous.
On the basis of the number of carpels, the ovary may be any one of the following types:

On the basis of the number of carpels, the ovary may be any one of the following types:
1. Monocarpeliary – with one carpel. e.g Pea, Bean, etc.
2. Bicarpellary – with two carpels. e.g. Vinca, Solanum, etc.
3. Tricarpellary – with three carpets. e.g Onion, Cucurbita, etc.
4. Tetracarpellary – with four carpels, e.g. Clarkia.
5. Pentacarpellary – with five carpels, e.g Hibiscus.
6. Multicarpellary – with many carpets. e.g Anona, Michelia, etc.

Placentation:
The mode of arrangement of placenta or placentae from which ovules are developed is called placentation. The different types of placentation are as follows:
1. Marginal – A single placenta located marginally. e.g: Pea, bean, groundnut, etc.
2. Basal – When the placenta is located on the floor of the locule 6f the ovary. e.g: Tridax, Helianthus (Sunflower) etc.
3. Axile – When placentae are located along the axis of the ovaiy, but partitioned by radial septae. e.g: Hibiscus, Tribulus, Allium cepa (onion), etc.
4. Free-central – When placentae are located along the axis of the ovary as in axile placentation, but are not partitioned by radial septae.
e.g: Dianthus
5. Parietal – When two or more placentae are longitudinally located on the inner side of ovary wall.
e.g: Cucurbita, Cucumis, Raphanus (radish), Brassica (mustard), etc.

Ovules:
The structures enclosed within the ovary which develop into seeds after fertilization are called ovules. They contain the embryosac with an egg.

The Angiosperm Seed And Fruits:

Fertilised ovule is called a seed. After fertilization, the integuments of the ovule develop into seed coat, fertilised egg into embryo and primary endosperm nucleus into endosperms.

1. Structure of a typical Dicotyledonous seed:
e.g: Bean seed.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.3

(A) Entire seed showing prominent raphe
(B) Seed coat removed to expose the kernel
(C) The two cotyledons spread apart removing the seed coat to show the radicle and plumule.

Bean seed is an exalbuminous seed or non endospermic seed, It is kidney shaped. It contains seed coat and embryo.

Seed Coat: It is the outer protective covering of the seed which is brownish red in colour. It differentiated into two layers namely, outer testa and inner tegmen. Testa is hard, brownish red layer developed from outer integument of the ovule. It is provided with a white ridge called raphe and a broad scar called hilum. Micropyle is present as a small pore near the hilum. Tegmen is the thin white membranous layer which encloses the embryo.

Embryo: It consists of embryonal axis and a pair of fleshy cotyledons. The pointed aid of the . axis is called radicle and the leafy end of the axis lying between the two cotyledons is called plumule. The part of embryonal axis present just above the attachment of cotyledons is called epicotyl and part of the axis below the attachment is called hypocotyL

2. Structural of a typical Monocotyledonous seed:
e.g: Maize grain.
1st PUC Biology Question Bank Chapter 5 Morphology of Flowering Plants.4
Maize grain is one seeded dry indehiscent fruit called caryopsis. It is an example for albuminous or endospermic seed. It has a flat, oblong, coloured body and consists of a grain wall called hull, endosperm and embryo.

Embryo: It occupies a small area of the grain on one side of the base. It consists of a single shield shaped cotyledon called scutellum and embryonic axis. Embryonic axis consists of pointed ends called radicle and plumule. Radicle is protected by a sheath called coleorhiza and plumule is by a sheath called coleoptile. At the time of germination, radicle develops into the root system and plumule into the shoot system.

Fruits:

A fruit is defined as a fertilized and ripened ovary. The fruit wall is called pericarp which may be thin, thick or fleshy. The pericarp is differentiated into outer epicarp, middle mesocarp and inner endocarp. The fruit is said to be true when it is developed entirely from the ovary, eg: Mango.
It is called a false fruit or pseudocarp when any other floral part also contributes towards the formation of the fruit, eg: Apple, where the thalamus becomes fleshy and edible.

Fruits that develop without fertilization are called parthenocarpic fruits. Such fruits are seedless since without fertilization ovules do not develop into seeds.

Fruits are classified into simple fruit, aggregate and compound or multiple fruits. A simple fruit develops from the gynoecium of one flower. The gynoecium is either simple or a compound pistil. An aggregate fruit is a collection of fruitlets which come from a single gynoecium of a flower.

The ovary is multicarpellary and apocarpous in nature. A multiple fruit is formed from an entire inflorescence having many flowers.

Simple Fleshy fruits: In these fruits the pericarp does not dry up even after the fruit is mature. They are of the following types.

Drupe: This is a fleshy fruit developed from a monocarpellary or a multicarpellary ovary. It may be formed from a superior or inferior ovary. The fruit wall is divided into epicarp, inesocarp and endocarp. The endocarp is invariably stony, eg: Mango, here the epicarp is leathery, the mesocarp is fleshy and juicy.

Berry: It is a fleshy fruit which develops like a drupe but the entire pericarp is fleshy, eg: Tomato, Sapota, Guava.

Simple Diy fruits: Here the pericarp dries up totally as the fruit matures. They are of 3 types – dehiscent, indehiscent and schizocarpic fruits.

1. Dry dehiscent fruits: These fruits delisec and liberate the seeds at maturity.
They are developed from uni, bi or multicarpellary syncarpus ovaries, depending on the mode of dehiscence they are of 4 types:

Loculicidal capsule: Here the fruit wall breaks open along the region of the loeule. eg: Cotton, ladies finger.
Porocidal capsule: Here the seeds come out through the pores developed on the upper part of the fruit wall, eg: Poppy.
Septicidal capsule: The seed dehisces along the septa an the axis of the fruit also splits eg: linseed.
Septifragal capsule: It resembles the septicidal type but the axis remains intact after dehiscence, eg: datura.

2. Dry indehiscent fruits: These fruits do not dehisce but the seeds are released only after the decay of the pericarp.

3. Dry schizocarpic fruits:
Here the fruits dehisce into units called mericarps which in turn splits to release the seeds. Aggregate fruits or etaerios’ fruits: It develops from the multicarpellary apocarpous gynoecium of a flower. From every gynoecium a cluster of fruits develop.

Multiple fruits:
These are also called compound fruits as all the flowers of the inflorescence contribute towards the formation on one fruit. These are false fruits.

Sorosis:
The fruit is developed from the entire female catkin inflorescence. The axis, bract and perianth become fleshy and juicy as in the case of Pineapple. In Jackfruit, the compactly arranged female flowers have styles which are spinous on the surface. The perianth of these flowers becomes the edible parts. Each perianth encloses a fruit which is massive with a single large seed.