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  3. Plant biologyMorphology Of The Flowering Plant

  4. Contain • Morphology • The Root • Modification Of Root • Functions Of Root • Rootless Plant • Plants that are all Roots INTRODUCTION


  6. Plant morphology (morphe-form+logos-study) is a branch of Botany which deals with the study of forms and features of different plant organs like roots, stems, leaves, flowers, seeds, fruits etc., including there development Morphology

  7. The root is that green cylindrical part of a plant which is given rise by radicle , the first to come out as a descending organ during germination of a seed THE ROOT

  8. Root Cap • Meristematic zone • Zone of Elongation • Root Hair • Zone of Mature Cells PARTS OF TYPICAL ROOT

  9. Root cap is a thimble- shaped or cap like protective structure present at the tip of root apex covering the root meristem. • It is a parenchymatous and multicellular . • The root cap secrets mucilage that lubricates the passage of root through the soil. • The soft and tender root would be unable to penetrate the hard soil if the root cap is absent . ROOT CAP

  10. It is a small region(about 1mm in length) positioned subterminally behind the root cap. • Meristematics zone or zone of cell division consists of isodimetric meristematicscells arranged closely or compactly and therefor, represents the growing point or zone of the root. • The Meristematic zone continuously produces new cells that are added outwards to the root cap and inward to the basal region of the root resulting in the longitudinal growth of the root MERISTEMATIC ZONE OR ZONE OF CELL DIVISION

  11. Lying just behind the meristematic zone, the zone of elongation is about 4-8mm in length and is made up of newly produced cells by growing point. • The cell of this zone lose the power of division but elongate rapidly thus increasing the length of the root. • The cell of this zone possess the power of absorption of water and mineral salts from the soil. ZONE OF ELONGATION

  12. Root hair zone is also called zone maturation or differentiation as the cells of this zone undergo maturation and differentiation into different type of primary tissues of the root, e.g., epiblema, cortex, endodermis, pericycle, phloem, xylem, etc.,. ROOT HAIR ZONE

  13. In aquatic plants root hair are usually absent. • Mycorrhizal roots lack root hair. • The number of root hairs are over 35,000 per square cm of root surface and many billions per plant. POINT TO REMEMBER

  14. Laying behind the root hair zone, the zone of mature cells constitutes the bulk of the root. • The outermost layer of it consists of thick walled or impermeable cell do not undergoing any further change. • The important function of this zone is to help anchoring the plant firmly in the soil and to give rise to lateral roots from the interior(pericycle). ZONE OF MATURE CELLS

  15. Tap Root System • Adventitious Root System TYPES OF ROOT(ROOT SYSTEMS)

  16. Given birth by radicle of the embryo. • Always underground. • Consist of single primary root. • Primary root produces distinct secondary roots, tertiary roots, and rootlets in acropetal succession. • Primary root is persistent. • It ay be surface feeder or deep feeder. TAP ROOT SYSTEM

  17. Given birth by any part of the plants other then radicle of the embryo. • May be underground or aerial. • Consist of roots forming a cluster. • Primary root absent and there is no any type of distinction. • Primary root though develops but is short-lived. • If underground it is usually surface feeder. ADVENTITIOS ROOT SYSTEM

  18. Modification Of Roots


  20. The tap root modify for the storage of food called storage or fleshy roots. The primary root is swollen due to stored food in it and the secondary root remain, carrot(Daucus carota), shalzum(Brassica rapa), chukander(Beta vulgaris) STORAGE OR FLESHY ROOTS

  21. The secondary , tertiary or some time the primary root in leguminaceous plants bear small nodule-like swellings. • These swellings are called root nodules or tubercles that contain nitrogen-fixing bacteria (namely, Rhizobium leguminosarum). NODULATED (TUBERCULATED) TAP ROOTS

  22. The bacteria pick up the free nitrogen occurring in the soil atmosphere and convert it into organic compounds of nitrogen. • This relationship is beneficial for both the bacteria and leguminous plant and therefor, is called mutualistic symbiosis( or reciprocal symbiosis). Cont……………


  24. Normally the adventitious root are fibrous and surface feeder( eg., cereals, grasses) but in some cases they get modified to perform special functions like storage food, mechanical support and vital activities .The modification of adventitious roots are as follow……………… CONTINUE…….

  25. Fleshy adventitious roots:- like tap roots sometimes the adventitious roots swollen and become thick due to storage of food. Depending upon there shape and place of swelling s, these roots are classified in to following categories:- 1. Tuberous(single root tubers) roots eg., sweet potato(ipomoea batata) 2. Fasciculated roots eg., Asparagus, Dahlia (A)FOR STORAGE OF FOOD

  26. Prop roots • Prop roots arise from large horizontal branches of the tree. • They hang down in vertical position. • After entering into the soil, these root give piller like appearance and do not terminate into fibrous root system. • Eg., Banyan tree(ficus benghalensis) (B) FOR MECHANICAL SUPPORT

  27. 2. Stilt roots • Stilt roots develop from the basal nodes or the stem near the soil. • They develop obliquely from the stem. • After entering into the soil, they terminate into the fibrous root system. • Eg., Pandanus, Zea mays etc.,. Cont…….

  28. 1.Primary functions • Anchorage • Absorption of water and minerals • Preventions of soil erosion 2. Secondary functions • Storage of food • Providing mechanical support • Help in floating • Help to climb FUNCTIONS OF ROOT

  29. Many hydrophytic plants e.g., Utricularia, Wolffia, Myriophylleum etc., Do not develop any roots as they need little absorption of water & minerals salts that is fulfilled by the general surface of the plants itself. • Aldrovanda is also rootless angiosperm. ROOTLESS PLANTS

  30. CONTENT • Stem • Buds • Forms of stem • Modification of stem • Function of stem THE STEM

  31. Stem can be define as that ascending part of the main axis(shoot axis) of plant which develop form the plumule of the embryo and is usually negatively geotropic and positively phototropic. STEM

  32. Stem grows in length by means of terminal buds. • It is clearly differentiated into nodes and internodes. • When young, the stem is green and photosynthesizes. • When mature, the stem bears flowers and fruits. • It may bears hair on external surface which are commonly multicelluar. POINTS TO BE REMBER

  33. A buds represents a condensed immature or embryonic shoot possessing a growing point enveloped by closely place immature leaves. However, a buds can be defined as a compact young shoot consisting shoot stem overlapped by crowded immature leaves surrounding the growing point. BUDS

  34. 1.On the basis of there nature • vegetative • Floral • Mixed 2. On the basis there position • Terminal • Lateral • Adventitious CLASSIFICATION OF BUDS

  35. Areal stem • Reduced stem:- Here the stem is very much reduced to a small disc which lies above the base of the root and is non photosynthetic. E.g., radish(raphanussativus ) etc. • Weak stem:- Here the areal stem are delicate thin, weak and thus are unable to erect. e.g., lableb , pasiflora etc. FORMS OF STEM

  36. Underground stem:- Underground subterranean stem are those that lies below the surface of the soil. They are not aerial, non green, store food and contribute in perennation. E.g., Banana( musaparadisiaca) . Cont……

  37. Prostrate or sub-aerial week stem • Trailers(=stragglers)., the main stem and its branches of some sub-aerial weak stem trails or spread horizontally along the ground without producing roots at intervals. • Creepers :- are those prostrate or sub-aerial weak stem whose main stem and its branches trails or spread horizontally along the ground producing root at interval. MODIFICATION OF STEM

  38. Upright weak stem modification • Twiners :- These stem are long flexible and twin around and upright – support like rope by a special type of growth movement (eg. Convolvulus arvensis ). The twiners can be considered as of sinistrorse - type and of dextrose-type. • Cilimbers:- contrary to the twiners that twin on the support by their own growth movement, the climber require the help of certain clasping of clinging structure(eg., Tendrils, Spines, Thorns, Hooks). eg., Smilax, Piper, Bignonia etc. Cont……

  39. Underground stem modification • Sobole is an underground- runner. It does not swell as it does not store any food material and remains thin. Eg., Agropyron, Imberata(Ulau grass). • Sucker • It is underground modify thin stem. • It may be said as runner like and underground runner . • It is apex of the sucker that grows into an aerial shoot. Cont………

  40. Rhizome • Rhizome is well developed and well branched underground modify stem. • Food material is stored in entire stem and branches. • Rhizome is placed generally obliquely or horizontally in soil. • Roots are produced all along rhizome. Eg,. Ginger. Cont……

  41. Primary functions • stem bears and supports foliage, flower and fruits. • Leave manufacture the food which is translocated through the phloem of the stem to root, fruit and storage organ. FUNCTIONS OF STEM

  42. Modification of stem for: a)storage (b) support (c)protection (d)spread and vegetative propagation

  43. Secondary functions • Stem store food in their parenchyma cells and underground modified form. Eg., Potato(solanumtuberosum), Ginger(zingiberofficinale), Banana(musaparadisiaca). • The underground stems like those of dryopteris, mentha etc. functions as orgons of perennation to overcome unfavourable conditions. Cont……

  44. CONTENT • Leaf • Kind of leaves • Types of leaves • Phyllotaxy • Leaf modification • Function of leaf THE LEAF

  45. Leaf is a green lateral flattened outgrowth borne on the node of a steam or its branches and is characteristically photosynthetic. Leaves originated from the shoot meristem as leaf primordia and gradually enlarge . They are the most important vegetative organ of the plant as they synthesize food in them. LEAF

  46. Cotyleadonary leaves:- these are the embryonic leaves(cotyledons) emerging at the time of seed germination. Two cotyledonary leaves are present in dicots while only one in monocots. KIND OF LEAVES

  47. These leaves contain flower or inflorescence in there axil and are called bract leaves. Usually they are small and green but exceptionally in some plants are large and bright coloured. BRACT LEAVES OR HYPSOPHYLLS

  48. Photosynthetic normal leaves borne on areal stem or its branches are called foliage leaves. The word leaf is normally used to refer to the foliage leaves. FOLIAGE LEAVES