{"id":38816,"date":"2024-02-17T05:30:05","date_gmt":"2024-02-17T00:00:05","guid":{"rendered":"https:\/\/www.aplustopper.com\/?p=38816"},"modified":"2024-02-17T14:54:57","modified_gmt":"2024-02-17T09:24:57","slug":"plus-one-botany-notes-chapter-3","status":"publish","type":"post","link":"https:\/\/www.aplustopper.com\/plus-one-botany-notes-chapter-3\/","title":{"rendered":"Plus One Botany Notes Chapter 3 Morphology of Flowering Plants"},"content":{"rendered":"
Define Morphology:
\nIt is study of external features of a plant i.e presence of roots, stems, leaves, flowers and fruits.<\/p>\n
The Root:<\/span> 2. Fibrous root system: 3. Adventitious roots: Regions of the Root:<\/span> 2. Region of Meristem: 3. Region of elongation: 4. Region of maturation: 5. Region root hairs: Modifications of Root:<\/span> 1. Mechanical support: (b) Stilt roots: 2. Storage of food: 3. Respiration: The Stem:<\/span> Function: Modifications of Stem:<\/span> 2. Climbing: 3. Protection: 5. Vegetative propagation:<\/p>\n The Leaf:<\/span> <\/p>\n Function of veins: Venation:<\/span> 2. Parallel Venation: Types of Leaves:<\/span><\/p>\n Can you see the bud in the axil of leaflet of compound leaf? Two types of compound leaves:<\/p>\n <\/p>\n Phyllotaxy:<\/span> <\/p>\n Modifications of Leaves:<\/span><\/p>\n <\/p>\n The Inflorescence:<\/span> How will you differentiate recemose inflorescence from cymose? The Flower:<\/span> What are the accessory and reproductive organs? Did you see single accessory organ of a flower: 2. Zyqomorphic: 3. Asymmetric (irregular): Bracteate and ebracteate flower: Classification of flower: 2. Perigynous flower: 3. Epigynous flowers: Parts of a Flower:<\/span> Calyx:<\/span> Corolla:<\/span> Aestivation: <\/p>\n Can vou find out aestivation type in papillionaceous corolla? Androecium:<\/span> Differentiate between epibetalous and epiphvllous condition: Free and fused nature of stamens: Variation in the length of filaments: Gynoecium:<\/span> The style connects the ovary to the stigma. The stigma is the receptive surface for pollen grains. Each ovary bears one or more ovules attached to a flattened, cushion-like placenta. Free and fused nature of carpel: What happens to ovule and ovary after fertilization? Placentation: The Fruit:<\/span> Meaning of Drupe: Different layers of pericarp: The Seed:<\/span> Structure of a Dicotyledonous Seed:<\/span> What is non endospermic seed? Structure of Monocotyledonous Seed:<\/span> It consists of Vy one large and shield shaped cotyledon known as scutellum and a short axis with a plumule and a radicle. The plumule is enclosed in sheaths called coleoptile and radicle are enclosed in sheaths called as coleorhiza. Some Technical Description Of A Typical Flowering Plant:<\/span> Description Of Some Important Families:<\/span> Vegetative Characters:<\/p>\n <\/p>\n <\/p>\n Economic importance: Solanaceae (\u2018potato family\u2019):<\/span> 2. Leaves: Floral Characters:<\/p>\n <\/p>\n <\/p>\n Economic Importance: Lilaceae (\u2018Lily family’):<\/span> Floral characters:<\/p>\n <\/p>\n <\/p>\n Economic Importance: Kerala Plus One Botany Notes Chapter 3 Morphology of Flowering Plants Define Morphology: It is study of external features of a plant i.e presence of roots, stems, leaves, flowers and fruits. The Root: Root system: In dicotyledonous plants, the direct elongation of the radicle leads to the formation of primary root which bears lateral roots […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[42728],"tags":[],"yoast_head":"\n
\nRoot system:
\nIn dicotyledonous plants, the direct elongation of the radicle leads to the formation of primary root which bears lateral roots that are secondary, tertiary, etc.
\n
\n1. Tap root system:
\nThe radical elongate and forms primary root or tap root that bears number of lateral roots. It is found in dicot root. eg: the mustard plant.<\/p>\n
\nIn monocotyledonous plants, the primary root is short lived from there thin fibre roots originates. eg: wheat plant.<\/p>\n
\nIn grass, Monstera and the banyan tree, roots arise from parts of the plant other than the radicle.
\n<\/p>\n
\n1. Region of Root cap:
\nIt is the covering of root apex that protects the tender apex.<\/p>\n
\nThis is the region just behind the the root cap that is capable of active cell division.<\/p>\n
\nThe cells proximal to this region undergo rapid elongation and enlargement for the growth<\/p>\n
\nThis is proximal to the region of elongation gradually differentiate and mature<\/p>\n
\nFrom the region of maturation root hairs arise. These root hairs absorb water and minerals from the soil.
\n<\/p>\n
\nRoots are modified for<\/p>\n\n
\n(a) Prop roots:
\nIn banyan tree, adventitious roots are modified and provide mechanical support<\/p>\n
\nIn maize and sugarcane adventitious roots are supporting and coming out from the lower nodes of the stem. .<\/p>\n
\nIn carrot, turnips tap roots are modified for food storage. In sweet potato adventitious roots are swollen and store food.<\/p>\n
\nRhizophora growing in swampy areas, many roots come out of the ground and grow vertically upwards. Such roots are called pneumatophores.
\nFunction:
\nIt help in the process of respiration.
\n
\n<\/p>\n
\nSalient features:<\/p>\n\n
\nSupport leaves, flowers and fruits. It also conducts water, minerals and do photosynthesis.<\/p>\n
\n1. Storage of food:
\nUnderground stems of potato, ginger, turmeric, zaminkand, Colocasia are modified to store food<\/p>\n
\nStem tendrils which develop from axillary buds, are slender and spirally coiled that help the plants to climb. eg: in gourds (cucumber, pumpkins, watermelon) and grapevines.<\/p>\n
\nAxillary buds of stem are modified into woody, straight and pointed thorns. eg: in Citrus, Bougainvillea Thev nrotect Dlants from browsina animals
\n
\n4. Photosynthesis:
\nSome stems are lattened (Opuntia), or fleshy cylindrical (Euphorbia) structures. They contain chlorophyll and carry out photosynthesis.<\/p>\n\n
\nSalient features:<\/p>\n\n
\nVeins act as channels of transport for water, minerals and food materials.
\nA typical leaf consists of three main parts:<\/p>\n\n
\n1. Reticulate Venation:
\nThe arrangement of veins and the veinlets in the lamina of leaf. Veinlets repeatedly branched to form a network. eg: dicotyledonous plants.<\/p>\n
\nWhen the veins run parallel to each other within a lamina. eg: monocotyledons plants.
\n<\/p>\n\n
\nA bud is not present in the axil of leaflets of the compound leaf.<\/p>\n\n
\nIt is the arrangement of leaves on the stem or branch Three types of phyllotaxy in plants alternate, opposite and whorled.<\/p>\n\n
\n
\nThe arrangement of flowers on the floral axis is termed as inflorescence. Two major types of inflorescences are<\/p>\n\n
\nIn racemose type, the main axis continues to grow, the flowers are arranged in an acropetal succession. In cymose type, the main axis terminates in a flower. The flowers arranged in a basipetal order.
\n<\/p>\n
\nThe flower is the reproductive unit in the angiosperms. It consists of different kinds of whorls (calyx, corolla, androecium and Gynoecium) arranged successively on the swollen end of the stalk or pedicel, called thalamus or receptacle.<\/p>\n
\nCalyx and corolla are accessory organs,while androecium and gynoecium are reproductive organs.<\/p>\n
\nIn lily plant, the calyx and corolla are not distinct, it is called as perianth. This is the single accessory organ of a flower. When a flower has both androecium and gynoecium, it is bisexual. A flower having either only stamens or only carpels is unisexual.
\n1. Actinomorphic Flower:
\nA flower can be divided into two equal radial halves in any radial plane passing through the centre, eg: mustard, datura, chilli.<\/p>\n
\nA flower can be divided into two similar halves only in one particular vertical plane, eg: pea, gulmohur, bean, Cassia.<\/p>\n
\nA flower cannot be divided into two similar halves by any vertical plane passing through the centre, as in canna. Afloweristrimerous, tetramerous or pentamerous when the floral appendages are in multiple of 3, 4 or 5, respectively.<\/p>\n
\nFlowers with reduced leaf found at the base of the pedicel, are called bracteate and those without bracts, ebracteate.<\/p>\n
\nIt is based on the position of calyx, corolla and androecium in respect of the ovary on thalamus
\n1. Hypogynous flower:
\nThe position of gynoecium is highest when compared to other. The ovary in such flowers is said to be superior, eg: mustard, china rose and brinjal.<\/p>\n
\nThe position of 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 position of ovary is half inferior, eg: plum, rose, peach.<\/p>\n
\nThe margin of thalamus grows upward and other parts of flower arise above the ovary. The position of ovary is inferior. eg: guava and cucumber, and the ray florets of sunflower.
\n<\/p>\n
\nEach flower has four floral whorls -calyx, corolla, androecium and gynoecium.
\n<\/p>\n
\nAct as protective whorl:
\nThe calyx is the outermost whorl of the flower and segments are called sepals. The sepals are green, leaf like and protect the flower in the bud stage. The calyx may be gamosepalous (sepals united) or polysepalous (sepals free).<\/p>\n
\nAct as an attractive whorl:
\nPetals are brightly coloured that attract insects for pollination. Corolla may be free (polypetalous) or united (gamopetalous).<\/p>\n
\nThe mode of arrangement of sepals or petals in floral bud is known as aestivation. The main types of aestivation are:<\/p>\n\n
\n
\nThere are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel). This is vexillary aestivation; Eg pea and bean flowers.<\/p>\n
\nStructure of stamen:
\nAndroecium is composed of stamens. Stamen is the male reproductive organ consists of 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.<\/p>\n
\nWhen stamens are attached to the petals, they are epipetalous as in brinjal, or epiphyllous when attached to the perianth as in the flowers of lily.<\/p>\n
\nThe stamens in a flower remain free called as polyandrous. If the stamens are united into one bundle called as monoadelphous. eg: china rose, or two bundles called as diadelphous eg: pea, or into more than two bundles called as polyadelphous eg: citrus.<\/p>\n
\neg: Salvia and mustard.<\/p>\n
\nStructure of carpel\/pistil:
\nGynoecium is the female reproductive part of the flower and is made up of one or more carpels. Acarpel consists of three parts namely stigma, style and ovary. Ovary is the enlarged basal part, on which lies the elongated tube, the style.<\/p>\n
\n<\/p>\n
\nIf carpels are free they are called apocarpous, eg lotus and rose. If carpels are fused they are called syncarpous. eg: mustard and tomato.<\/p>\n
\nAfter fertilisation, the ovules develop Into seeds and the ovary matures into a fruit.<\/p>\n
\nThe arrangement of ovules within the ovary is known as placentation. Different types of placentation are marginal, axile, parietal, basal, central and free central.<\/p>\n\n\n
\n Marginal placentation: the placenta forms a ridge along the ventral suture of the ovary and the ovules are borne on this ridge eg- pea.
\nAxile placentation: When the placenta is axial and the ovules are attached to it in a multilocular ovary eg china rose, tomato and lemon.
\nParietal placentation: Ovary is one-chambered and the ovules develop on the inner wall of the ovary e.g., mustard and Argemone.
\nFree central placentation: When the ovules are borne on central axis and septa are absent Eg Dianthus and Primrose
\nBasal placentation: The placenta develops at the base of ovary and a single ovule is attached to it eg sunflower, marigold<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\nIt is a ripened ovary developed after fertilisation.
\nParthenocarpic fruit:
\nIf a fruit is formed without fertilisation of the ovary, it is called a parthenocarpic fruit. The fruit consists of a wall called pericarp and seeds.<\/p>\n
\nFruit that develops from monocarpellary superior ovaries and are one seeded. Eg:- mango and coconut.<\/p>\n
\nIn mango the pericarp is well differentiated into an outer thin epicarp, a middle fleshy edible mesocarp and an inner stony hard endocarp. In coconut fruit is drupe, the mesocarp is fibrous.
\n<\/p>\n
\nSeed consists of a seed coat and an embryo. The embryo is made up of a radicle, an embryonal axis, one cotyledons as in wheat, maize or two cotyledons as in gram and pea.<\/p>\n
\nThe seed coat has two layers, the outer testa and the inner tegmen. The hilum is a scar on the seed coat .Above the hilum is a small pore called the micropyle. It consists of an embryonal axis and two cotyledons. The cotyledons are fleshy and contains reserve food materials. At the two ends of the embryonal axis are present the radicle and the plumule.<\/p>\n
\nIn plants such as bean, gram and pea, the endosperm is not present in mature seeds and such seeds are called non endospermous.
\n<\/p>\n
\nMonocotyledonous seeds are endospermic but it is non-endospermic in orchids. The seed coat is membranous and fused with the fruit wall. The outer covering of endosperm separates the embryo by a proteinous layer called aleurone layer The embryo is situated in one end of the endosperm.<\/p>\n
\n<\/p>\n
\nIn the floral formula, Br stands for bracteate K stands for calyx, C for corolla, P for perianth, A for androecium and G for Gynoecium, for superior ovary and for inferior ovary, for male, for female, for bisexual plants, for for actinomorphicand forforzygomorphic nature of flower<\/p>\n
\nFabaceae (Papilonoideae ):<\/span>
\nIt is a subfamily of family Leguminosae.<\/p>\n\n
\nSources of pulses (gram, arhar.sem, moong, soyabean; Edible oil (soyabean, groundnut); dye (indigofera); Fibres (sunhemp); Fodder (Sesbania, Trifolium), Ornamentals (lupin, sweet pea) Medicine (muliathi).<\/p>\n
\nVegetative Characters:
\n1. Stem:
\nherbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, underground stem in potato (Solatium tuberosum).<\/p>\n
\nalternate, simple, rarely pinnately compound, exstipulate; venation reticulate<\/p>\n\n
\nsource of food (tomato, brinjal, potato)spice (chilli); Medicine (belladonna, ashwagandha) Fumigatory (tobacco); ornamentals (petunia).<\/p>\n
\nVegetative characters:
\nPerennial herbs with underground bulbs\/corms\/rhizomes. Leaves mostly basal, alternate, linear, exstipulate with parallel venation.<\/p>\n\n
\nOrnamentals (tulip, Gloriosa), Source of medicine (Aloe), Vegetables (Asparagus), and colchicine (Colchicum autumnale).<\/p>\nPlus One Botany Notes<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"