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Plant anatomy

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ManojDas87

The document discusses the internal structure of dicot and monocot roots. It describes the key layers and tissues found in roots, including the epiblema, cortex, endodermis, pericycle, vascular bundles, xylem, phloem and pith. In dicot roots, the vascular bundles vary from 2-6 and are radial, while in monocot roots they vary from 8-20 and are also radial. The pith is poorly developed or absent in dicots but highly developed in monocots.

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Internal structure of root Presenter -Dr. Manoj Kumar Das
Plant anatomy Primary internal structure of root Diagnostic features of root- The epiblema or piliferous layer is present. Here the stomata and cuticle layer are absent. The root hairs are unicellular. The endodermis has casparian layer. The vascular bundles are radial type. The xylem is exarch Anatomy of dicot root
Diagnostic features of dicot root Number of VB varies from 2-6. The pericycle produces lateral roots and cambium during the secondary growth The pith is poorly developed or absent. The secondary growth is present
Internal structure of a typical dicot root shows the following structure 1. Epiblema or piliferous layer- It is the outermost protective supporting and uniseriate layer. It is made up of compactly arranged parenchymatous cells. Some cells produces unicellular root hairs Both epiblema and root hairs absorb sap from the soil. 2. Cortex- It lies below the epiblema. It occupies the massive part of the root. It is made of loosely arranged parenchymatous cells with a large number of intercellular spaces that allow gaseous exchange. The cortical cells help in the storage of food materials.
3. Endodermis- I It is the innermost layer of the cortex. It iis composed of uniseriate and barrel shaped parenchymatous cells. Most of the cell are characterized by the presence of band like thickenings of suberin and lignin on their radial wall and tangential walls. These thickenings are called as casperian strips. But some cells laying opposite to the proto xylem remain un thickened and are called as passage cells that allow diffusion of sap.
4. Pericycle- It lies just below the endodermis. It consists of a uniseriate parenchymatous cells. The lateral roots, vascular cambium and cork cambium are originated from this layer. 5. Conjunctive tissue- The xylem and phloem are separated from each other by thin walled parenchymatous conjunctive tissue. 6.Vascular bundles- VBs are radial type. Number of xylem and phloem varies from 2-6 i.e diarch to hexarch. Both xylem and phloem are equal in number. The xylem is exarch. Xylem- The protoxylem vessels bear annular and spiral Thickening while metaxylem vessels have reticulate and pitted thickenings, xylem parenchyma and fibres are absent .
Phloem- It lies alternate to xylem . The patches are smaller and consist of sieve tube , companion cells and phloem parenchyma. The phloem fibers are absent. Pith The central mass of parenchymatous tissue is called pith. In dicot roots , the pith is absent on highly reduced .
Plant anatomy
Diagnostic features of monocot root Number of VB varies from 8-20. The pericycle produces only lateral roots The pith is developed. The secondary growth is absent.
Internal structure of atypical monocot root shows the following structure 1. Epiblema or piliferous layer- It is the outermost protective supporting and uniseriate layer. It is made up of compactly arranged parenchymatous cells. Some cells produces unicellular root hairs Both epiblema and root hairs absorb sap from the soil. 2. Cortex- It lies below the epiblema. It occupies the massive part of the root. It is made of loosely arranged parenchymatous cells with a large number of intercellular spaces that allow gaseous exchange. The cortical cells help in the storage of food materials.
3. Endodermis- I It is the innermost layer of the cortex. It iis composed of uniseriate and barrel shaped parenchymatous cells. Most of the cell are characterized by the presence of band like thickenings of suberin and lignin on their radial wall and tangential walls. These thickenings are called as casperian strips. But some cells laying opposite to the proto xylem remain un thickened and are called as passage cells that allow diffusion of sap.
4. Pericycle- It lies just below the endodermis. It consists of a uniseriate parenchymatous cells. The lateral roots are originated from this layer. 5. Conjunctive tissue- The xylem and phloem are separated from each other by thin walled parenchymatous conjunctive tissue. 6.Vascular bundles- VBs are radial type. Number of xylem and phloem varies from 8-20 i.e polyarch. Both xylem and phloem are equal in number. The xylem is exarch. Xylem- The protoxylem vessels bear annular and spiral Thickening while metaxylem vessels have reticulate and pitted thickenings, xylem parenchyma and fibers are absent .
Phloem- It lies alternate to xylem . The patches are smaller and consist of sieve tube , companion cells and phloem parenchyma. The phloem fibers are absent. Pith The central mass of parenchymatous tissue is called pith. In monocot roots , the pith is highly developed.
Plant anatomy

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Plant anatomy

  • 2. Plant anatomy Primary internal structure of root Diagnostic features of root- The epiblema or piliferous layer is present. Here the stomata and cuticle layer are absent. The root hairs are unicellular. The endodermis has casparian layer. The vascular bundles are radial type. The xylem is exarch Anatomy of dicot root
  • 3. Diagnostic features of dicot root Number of VB varies from 2-6. The pericycle produces lateral roots and cambium during the secondary growth The pith is poorly developed or absent. The secondary growth is present
  • 4. Internal structure of a typical dicot root shows the following structure 1. Epiblema or piliferous layer- It is the outermost protective supporting and uniseriate layer. It is made up of compactly arranged parenchymatous cells. Some cells produces unicellular root hairs Both epiblema and root hairs absorb sap from the soil. 2. Cortex- It lies below the epiblema. It occupies the massive part of the root. It is made of loosely arranged parenchymatous cells with a large number of intercellular spaces that allow gaseous exchange. The cortical cells help in the storage of food materials.
  • 5. 3. Endodermis- I It is the innermost layer of the cortex. It iis composed of uniseriate and barrel shaped parenchymatous cells. Most of the cell are characterized by the presence of band like thickenings of suberin and lignin on their radial wall and tangential walls. These thickenings are called as casperian strips. But some cells laying opposite to the proto xylem remain un thickened and are called as passage cells that allow diffusion of sap.
  • 6. 4. Pericycle- It lies just below the endodermis. It consists of a uniseriate parenchymatous cells. The lateral roots, vascular cambium and cork cambium are originated from this layer. 5. Conjunctive tissue- The xylem and phloem are separated from each other by thin walled parenchymatous conjunctive tissue. 6.Vascular bundles- VBs are radial type. Number of xylem and phloem varies from 2-6 i.e diarch to hexarch. Both xylem and phloem are equal in number. The xylem is exarch. Xylem- The protoxylem vessels bear annular and spiral Thickening while metaxylem vessels have reticulate and pitted thickenings, xylem parenchyma and fibres are absent .
  • 7. Phloem- It lies alternate to xylem . The patches are smaller and consist of sieve tube , companion cells and phloem parenchyma. The phloem fibers are absent. Pith The central mass of parenchymatous tissue is called pith. In dicot roots , the pith is absent on highly reduced .
  • 9. Diagnostic features of monocot root Number of VB varies from 8-20. The pericycle produces only lateral roots The pith is developed. The secondary growth is absent.
  • 10. Internal structure of atypical monocot root shows the following structure 1. Epiblema or piliferous layer- It is the outermost protective supporting and uniseriate layer. It is made up of compactly arranged parenchymatous cells. Some cells produces unicellular root hairs Both epiblema and root hairs absorb sap from the soil. 2. Cortex- It lies below the epiblema. It occupies the massive part of the root. It is made of loosely arranged parenchymatous cells with a large number of intercellular spaces that allow gaseous exchange. The cortical cells help in the storage of food materials.
  • 11. 3. Endodermis- I It is the innermost layer of the cortex. It iis composed of uniseriate and barrel shaped parenchymatous cells. Most of the cell are characterized by the presence of band like thickenings of suberin and lignin on their radial wall and tangential walls. These thickenings are called as casperian strips. But some cells laying opposite to the proto xylem remain un thickened and are called as passage cells that allow diffusion of sap.
  • 12. 4. Pericycle- It lies just below the endodermis. It consists of a uniseriate parenchymatous cells. The lateral roots are originated from this layer. 5. Conjunctive tissue- The xylem and phloem are separated from each other by thin walled parenchymatous conjunctive tissue. 6.Vascular bundles- VBs are radial type. Number of xylem and phloem varies from 8-20 i.e polyarch. Both xylem and phloem are equal in number. The xylem is exarch. Xylem- The protoxylem vessels bear annular and spiral Thickening while metaxylem vessels have reticulate and pitted thickenings, xylem parenchyma and fibers are absent .
  • 13. Phloem- It lies alternate to xylem . The patches are smaller and consist of sieve tube , companion cells and phloem parenchyma. The phloem fibers are absent. Pith The central mass of parenchymatous tissue is called pith. In monocot roots , the pith is highly developed.