Plant Biology Lecture Outline on Tissues PDF

Because learning changes everything. ® Chapter 4 Lecture Outline Tissues FIFTEENTH EDITION James E. Bidlack, Shelly H. Jansky © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduct...

Because learning changes everything. ® Chapter 4 Lecture Outline Tissues FIFTEENTH EDITION James E. Bidlack, Shelly H. Jansky © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.  Outline Introduction to Tissues Meristematic Tissues Apical Meristems Lateral Meristems Tissues Produced by Meristems Simple Tissues Complex Tissues © McGraw Hill Steven P. Lynch 2  Introduction to Tissues Plants have three or four major groups of organs: Roots Stems Leaves Flowers Each organ is composed of tissues. A tissue is a group of cells performing a similar function. There may be more than one tissue per organ. © McGraw Hill 3  Roots and Stems Three basic tissue patterns in roots and stems. Woody dicots Herbaceous dicots Monocots © McGraw Hill 4  Meristematic Tissues Meristems - Permanent regions of growth and active cell division Cells are typically small, 6-sided, box-like, with very large nuclei form and small to absent vacuoles As cells mature they assume different shapes. Vacuoles increase in size and may occupy more than 90% of the volume of the cell. © McGraw Hill 5  Apical Meristems Found at the tips of roots and shoots Roots and shoots increase in length as the apical meristems produce new cells = primary growth Embryo Leaves and buds and 3 primary meristems develop from apical meristems. © McGraw Hill 6  Primary Meristems Primary meristems are called Protoderm Ground Meristem Procambium Primary meristems produce primary tissues. Access the text alternative for slide images. © McGraw Hill 7  Lateral Meristems Produce secondary tissues that increase the girth of roots and stems (= secondary growth) Include the vascular cambium and the cork cambium. © McGraw Hill 8  Vascular Cambium Sometimes just known as cambium. Produces secondary tissues that function primarily in support and conduction. Composed of a thin cylinder of brick-shaped cells that extends the length of stems and roots Cambial cylinder often branches, except at the tips. Tissues produced are responsible for most of the increases in girth as a plant grows. Individual remaining cells of the cambium are called initials, and their sister cells are called derivatives. © McGraw Hill 9  Cork Cambium A thin cylinder that runs the length of roots and stems of woody plants Lies outside vascular cambium just inside the outer bark Produces bark © McGraw Hill 10  Intercalary Meristems Grasses and related plants do not have vascular cambium nor cork cambium. They have apical meristems. Intercalary meristems are present. Occur in vicinity of nodes (leaf attachment area) along stems Add to stem length © McGraw Hill 11  Tissues Produced by Meristems After they arise from the meristems, in maturing cells assume various shapes and sizes. Shape is related to function. Simple tissues are composed of one type of cell. Complex tissues have two or more cell types. © McGraw Hill 12  Simple Tissues Parenchyma - Composed of parenchyma cells Parenchyma cells: Thin, pliable walls Usually 14-sided at maturity Living cytoplasm, often containing large vacuoles and various secretions May remain alive a long time Have spaces between them © McGraw Hill © James E. Bidlack 13  Types of Parenchyma Tissue and Cells Aerenchyma - Parenchyma tissue with extensive connected air spaces, usually in aquatic plants Chlorenchyma - Parenchyma cells containing chloroplasts that function in photosynthesis Transfer cells - Develop irregular extensions of inner wall that greatly increase surface area of plasma membrane Nectaries of flowers © McGraw Hill 14  Collenchyma Tissue Characteristics of collenchyma cells: Living cytoplasm May remain alive a long time Cell walls thick, with uneven thickness Pliable and strong, thus provide flexible support © McGraw Hill © James E. Bidlack 15  Sclerenchyma Tissue Characteristics of sclerenchyma cells Thick, tough, secondary walls, normally impregnated with lignin Dead at maturity Function in support Two types: Sclereids Fibers © McGraw Hill 16  Sclereids Scattered in tissue Cells as long as wide Include stone cells Access the text alternative for slide images. © McGraw Hill (a) © Kingsley Stern; (b) © G. S. Ellmore 17  Fibers Found in roots, stems, leaves, and fruits Much longer that wide and contain lumen (tiny cavity) Have been used by humans for thousands of years as rope, string, canvas, textiles, etc. Access the text alternative for slide images. © McGraw Hill (a) ©Kingsley Stern; (b) Photomicrograph by G.S. Ellmore 18  Complex Tissues Complex tissues - Composed of two or more kinds of cells Some complex tissues are produced by apical meristems Include xylem and phloem, epidermis, and periderm, © McGraw Hill 19  Xylem and Phloem Transport water, ions, and soluble food through plants In woody plants, most complex tissues are produced by the vascular cambium and are called vascular tissues © McGraw Hill 20  Epidermis 1 A protective layer covering all plant organs Consists of parenchyma or parenchyma-like cells Includes specialized cells that regulated the movement of gases in and out of the plant, secretory glands, hairs, crystal-isolating cells, and cells that increase the surface area of roots. © McGraw Hill 21  Periderm 2 Comprises the outer bark of woody plants. Consists mainly of cork cells Has pockets of parenchyma-like cells © McGraw Hill 22  Xylem Chief conducting tissue for water and minerals that are absorbed by the roots Composed of parenchyma cells, fibers, vessels, tracheids and ray cells © McGraw Hill 23  Vessels Vessels – Long tubes made of vessel elements Vessel elements: Thick secondary cell walls Open at both ends Secondary walls develop irregularly Perforation plate between end walls © McGraw Hill © James E. Bidlack 24  Tracheids Tapered at the ends with pairs of pits that allow water to pass from cell to cell Pits – Areas without secondary cell Dead at maturity Thick secondary cell walls May have spiral thickening on cell wall Access the text alternative for slide images. © McGraw Hill 25  Rays Function in lateral conduction and food storage Composed of long-lived parenchyma cells Produced in horizontal rays by ray initials of the vascular cambium In woody plants they radiate out from the center like spokes of a wheel © McGraw Hill 26  Phloem Conducts dissolved food materials produced by photosynthesis throughout plant Composed of sieve tube members, companion cells, fibers, parenchyma cells and ray cells © McGraw Hill 27  Companion Cells and Sieve Tube Members Companion cells Narrow, tapered cells associated with sieve tube members Sieve Tube Members: Lack secondary cell walls and nuclei Lay end to end to form sieve tubes Walls have sieve plates with small pores Callose forms callus plug - Prevents leaking of sieve tube contents when cell injured Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 28  Epidermis Protective layer that is one cell-layer thick Covers all plant organs Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 29  Components of the Epidermis Usually one cell thick Some plants produce velamen roots which are several cells thick Others produce leaves with a multiple-layered epidermis Cutin - Fatty substance on the surface of outer walls of epidermis that forms cuticle Wax secreted on cuticle Cuticle and wax prevent water loss by evaporation Resistant to bacteria and other disease organisms © McGraw Hill 30  Other Epidermal Components Root epidermal cells produce root hairs. Increase absorptive area of root surface Above ground parts of plants may have trichomes. Outgrowths consisting of one to several cells (a)Thierry Berrod, Mona Lisa Production/Science Source © McGraw Hill © Kingsley Stern 31  Stomata and Other Modifications Leaves have stomata bordered by pairs of guard cells. © McGraw Hill 32  Glands or Modified Hairs Some epidermal cells are modified as glands or modified hairs. © McGraw Hill (b) Andrew Syred/Science Source 33  Periderm Replaces epidermis when cork cambium begins producing new tissue Constitutes outer bark Primarily composed of cork cells Dead at maturity While still alive, cytoplasm secretes suberin (fatty substance) into walls. Makes cork cells waterproof and helps protect phloem © McGraw Hill 34  Lenticels Loosely arranged pockets of parenchyma cells formed by cork cambium that protrude through the surface of periderm. Allows for gaseous exchange. Access the text alternative for slide images. © McGraw Hill (a) JohnatAPW/Getty Images; (b) ©James E. Bidlack 35  Secretory Cells and Tissue Secretory cells may function individually or as part of a secretory tissue. Flower nectar Citrus oils Glandular hair mucilage Latex Resins © McGraw Hill 36  Review Organs and Tissues Meristematic Tissues Apical Meristems Lateral Meristems Intercalary Meristems Tissues Produced by Meristems Simple Tissues Complex Tissues © McGraw Hill 37  End of Main Content Because learning changes everything. ® www.mheducation.com © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.