Plant Anatomy Tissues & Roots

1. Plant AnatomyTissues & Roots Chapter 23. 1 & Chapter 23.2

2. Parts of the Plant - LAB • Pre-Lab • 1. Sketch the image to your left on the back of your lab handout. It must be labeled. • 2. What characteristics would you use to classify vegetables/fruits as parts of the plant?

3. Vocabulary Part A: 23.1-23.2 • Meristematic Tissue • Apical Meristem • Epidermal Cell • Cuticle • Trichome • Vessel Element • Sieve Tube Element • Companion Cell • Taproot • Fibrous Hair • Root Hair • Cortex • Endodermis • Vascular Cylinder • Root Cap • CasparianStrip

4. Tissues Chapter 23-1

5. Structure of Seed Plants • Cells of a seed plant are grouped into organs and tissues. • Three organs of seed plants are: • Roots • Stems • Leaves

6. Tissue Systems • Dermal – outer covering functions to protect plant and exchange gases and water (like skin). • Vascular – transports water and nutrients throughout plant (like bloodstream). • Ground – cells act as support for plant (like skeleton).

7. Dermal Tissue • Dermal tissue typically consists of a single layer of epidermal cells. • The cuticle is a thick, waxy layer that protects against water loss and injury. • The function of trichomesis to protect the leaf. • In roots, dermal tissue consists of root hairs which increase surface area and aid in water absorption.

9. Exit Slip 3/12 • 1. What are the 3 organs found in plants? • 2. What are the 3 types of tissues found in plants? • 3. What function does dermal tissue serve? • 4. What function does vascular tissue serve? • 5. What function does ground tissue serve?

10. Vascular Tissue • Tissue Cells: • Tracheids – long, narrow xylem cells with walls that are impermeable to water. • Vessel elements – xylem cells arranged end to end on top of one another. • Sieve tube elements – main phloem cells. • Companion cells – phloem cells that surround sieve tube elements.

11. Vascular Tissue • Water can move from one tracheid into a neighboring cell because the cell walls are pierced by openings that connect neighboring cells to one another. • Materials can move from one sieve tube element into the next through small holes in the end walls. • Companion cells support the phloem cells.

13. Ground Tissue • The cells that lie between dermal and vascular tissue make up ground tissue. • Ground Tissue Cells:

14. Parenchyma Collenchyma Sclerenchyma

16. Meristematic Tissue • Most plants have indeterminate growth (grow as long as they live). • New cells are produced in areas called meristems – clusters of tissue that are responsible for a plant growth. • New cells undergo a process of differentiation. • Differentiation- process of maturation and production of specialized structures. • Apical meristem – area of cells found in roots and shoots that increases their length. • Meristematic tissue – undifferentiated (has not yet become specialized for cell functions) tissue found in meristems. • Only plant tissue that produces new cells by mitosis.

18. Tissue Concept Map • 4 Types: • 1. Dermal – What type of cells are found here? • 2. Ground – What are the 3 types of cells? • 3. Vascular – Divided into 2 tissue types. What are the cells associated with each type of tissue. • 4. Meristematic

19. Dermaltissue Meristematictissue Vasculartissue Groundtissue Epidermalcells Parenchymacells Collenchymacells Sclerenchymacells Xylem Phloem Companioncells Vesselelements Sieve tubeelements Tracheids Plant Tissues include includes includes includes includes includes

20. Roots Chapter 23-2

21. What is a Root? • Absorb water and nutrients from soil and transport to rest of plant. • Anchor plants in ground, holding soil in place and preventing erosion. • Holds plant upright and prevents them from being knocked over by wind or rain.

22. Types of Roots • There are 2 main types of roots: • 1. Taproots- found mainly in dicots; primary root grows long and thick, secondary roots remain small; can reach water far below the surface (carrots, dandelions). • 2. Fibrous roots- branch so no single root looks longer than the rest; help prevent topsoil from eroding (grasses).

23. Root Structure • Consists of a central vascular cylinder surrounded by ground tissue and the epidermis. • Epidermis- outer layer made of dermal tissue, root hairs increase the surface area. • Cortex- made of ground tissue, spongy in texture. • Endodermis- surrounds vascular tissue in center (vascular cylinder). • Vascular cylinder- made of xylem and phloem. • Root cap- tough tissue that protects root as it pushes through soil. • Root hairs – tiny cellular projections that cover surface of root and penetrate soil to produce larger surface area.

24. Root Growth/Zones • Zone of CellDivision- Only cells in root tip divide (by mitosis). • Zone of Elongation– area just behind root tip, newly divided cells increase in length. • Zone of Maturation– cells in this area undergo differentiation becoming specialized in structure and function.

26. Uptake of Plant Nutrients • Soil contains several nutrients that are essential for plant growth, these include calcium, nitrogen, potassium, and phosphorous. • Each nutrient plays a role and the absence of one or more nutrients will result in soil deficiencies. • Minerals and nutrients move into the root by active transport whereas water moves by osmosis.

27. Plant Nutrients

28. Vascular Cylinder • Watermoves by osmosis into root epidermis cortex endodermis  vascular cylinder. • Endodermis is surrounded by a waterproof strip called the Casparian strip. • Water is trapped in vascular cylinder causing a one-way passage of materials into the endodermis.