Unit-IV-Tissues PDF - Plant Tissues

UNIT IV. Plant Tissues Melvin M. Morella - Faculty College of Arts and Sciences Department of Biological Sciences COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Plants ❑ Nonvascular Plants Simple; most grow in moist places...

UNIT IV. Plant Tissues Melvin M. Morella - Faculty College of Arts and Sciences Department of Biological Sciences COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Plants ❑ Nonvascular Plants Simple; most grow in moist places No vascular systems/tissues Moss Liverworts Examples: Mosses, liverworts, green Algae Green Algae COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Plants ❑ Vascular Plants Three main parts: roots, stems and leaves Examples: Trees and grasses COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Plants ❑ Ferns Thought to be the first vascular plants to have evolved Contains cuticle Does not have pollen, seeds, flowers, and fruits Uses spores for reproduction COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Plants ❑ Gymnosperms Seed-bearing plants Also known as naked seeds Does not have flowers and fruits COLLEGE OF ARTS & SCIENCES Department of Biological Sciences OUTLINE 1 Meristem 4 Vascular Tissue Ground Tissue 4 Secretory Cells and 2 Tissues 3 Dermal Tissue COLLEGE OF ARTS & SCIENCES Department of Biological Sciences 1 MERISTEM COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Meristem Region of plant that contains meristematic tissues Tissues containing meristematic cells Meristematic cells are undifferentiated cells, does not yet have specific function Responsible for developing new tissues and plant growth Responsible for primary growth and secondary growth Three types of meristems: Apical, lateral, intercalary COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Meristem ❑ Apical Meristems Growing tip (shoot system) (Root system) Root Apical Meristem - Roots Shoot Apical Meristem - Shoots Consist of: Protoderm → Dermal tissues, Procambium → primary vascular tissues, Ground Meristems → ground tissue COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Meristem ❑ Cross Section COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Meristem ❑ Lateral Meristems Side by side growth Secondary growth - the increase of plant’s girth Consist of: Vascular cambium → secondary vascular tissue, cork cambium → periderm COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Meristem ❑ Intercalary Meristems Promotes stem length and increase the height of the plant Located at intervals along stems; internodes COLLEGE OF ARTS & SCIENCES Department of Biological Sciences 2 Ground Tissue COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue Permanent tissue Makes up most of the plant structure Consist of: parenchyma tissue, collenchyma tissue, sclerenchyma COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Parenchyma Tissue Permanent tissue Consist of parenchyma cells – (homogenous) Responsible for tissue repair, photosynthesis, storage COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Parenchyma Tissue Thin-walled Have intercellular air spaces Can either be oval or rectangular in shape Can be found on leaves, stem, and roots COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Collenchyma Tissue Permanent tissue Consist of collenchyma cells – (homogenous) Provides structural support and elasticity for the plant especially in growing areas COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Collenchyma Tissue Elongated thick cells Can either be spherical or elongated in shape Can be found on stems, leaves, branches, COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Sclerenchyma Tissue Permanent tissue Consist of sclerenchyma cells with two types: Fibers - long, tapered cells, found in the wood, inner bark and leaf veins of flowering plants Sclereids - short cells, found in the shells of nuts and stone fruits Provides structural support and protection COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Ground Tissue ❑ Sclerenchyma Tissue Thick, lignified walls Irregular or branched in shape COLLEGE OF ARTS & SCIENCES Department of Biological Sciences 3 DERMAL TISSUE COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Periderm ❑ Cuticle ❑ Trichomes ❑ Stomata COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Periderm Protective tissue that protects the plant from the outside environment Replaces epidermis at maturity Consist of: Cork (Phellem) – outermost, protection, impermeable to water and gases Cork Cambium (Phellogen) – below the cork, produces new cork cells and phelloderm cells, for secondary growth Phelloderm – innermost, beneath cork cambium, assist in storage of food and water, made up of parenchyma cells COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Periderm COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Lenticels COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Cuticle Waxy, hydrophobic layer that covers the epidermis Prevents water from escaping No organelles Protective layer COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Cuticle COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Trichomes Hair-like structures found on the skin of the plant Has two types with specific functions: ▪ Glandular Trichomes – Secretes oil ▪ Non-glandular trichomes – Does not secrete oil COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Stomata Plays an important role in photosynthesis, respiration, transpiration Consist of: stomatal pore, epidermal cell, guard cell COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Stomata Stomatal Pore – Opening part of the stomata for gas exchange and transpiration Guard Cells – Specialized cells that controls the opening and closing of the stoma Epidermal Cell – Surround the stoma COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue ❑ Stomata COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Dermal Tissue COLLEGE OF ARTS & SCIENCES Department of Biological Sciences 4 VASCULAR TISSUE COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Vascular Tissue Not present in all kinds of plants, present in vascular plants Embedded within ground tissue Transports nutrients, minerals, and water throughout the plant Consist of: Xylem, Phloem COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Vascular Tissue ❑ Xylem Elongated cells Large lumen Dead at maturity and has no protoplasm Thickened with lignin: Strong polymer, key component of xylem for its overall composition COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Vascular Tissue ❑ Xylem One way transport of water and minerals Provides structural support Two types of water conducting cells: ▪ Vessel elements – short, wide, fast transport ▪ Tracheid – long, narrow, transport between cells COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Vascular Tissue ❑ Phloem Have sieve tube elements for transporting sugars throughout the plant Two-way movement for sugar distribution Have companion cells (living cells) that provide nutrients for the phloem and maintains pressure gradient COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Vascular Tissue cross section COLLEGE OF ARTS & SCIENCES Department of Biological Sciences  Secretory Cells and 5 Tissues COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Secretory Cells and Tissues ❑ External Secretory Structure Glands Release secretions ❑ Internal Secretory Structures Stores secretions COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Secretory Cells and Tissues ❑ External Secretory Structure 1 2 Glands 1. Nectaries – Secretes nectar, flowers 2. Hydathodes – Secretes excess water, leaves 3 4 3. Glandular Trichomes – Secretes oils or digestive enzymes for protection 4. Laticifers – Secretes latex COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Secretory Cells and Tissues ❑ Internal Secretory Structures 1 2 1. Idioblasts – Stores tannins, oils, calcium oxalate crystals for defense 2. Glandular trichomes – Contains internal secretory cells that stores essential oils 3 3. Oil cells – stores oil COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Some Important Terms ❑ Simple Tissues: composed of only one kind of cell. (homogenous) Parenchyma Tissues Collenchyma Tissues Sclerenchyma Tissues ❑ Complex Tissues: have two or more kinds of cells. (heterogenous) Xylem Phloem COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Some Important Terms ❑ Permanent Tissues: Derived from meristematic tissues, having their own specific functions, fully grown tissues Dermal Tissues: Epidermis Ground Tissues: Parenchyma Tissues, Collenchyma Tissues, Sclerenchyma Tissues Vascular Tissues: Primary and secondary xylem, primary and secondary phloem Vascular Cambium: Secondary vascular tissues Vascular Cylinder: Primary vascular tissues COLLEGE OF ARTS & SCIENCES Department of Biological Sciences Get in Touch With Us Send us a message or visit us City of Batac, Ilocos Norte, Philippines (63) 77-600-0459 [email protected] Follow us for updates facebook.com/MMSUofficial www.mmsu.edu.ph