1. Chapter 23 BIO 392 Flowering plants Cone- bearing plants Ferns and their relatives Mosses and their relatives Green algae ancestor Flowers; Seeds Enclosed in Fruit Seeds Water-Conducting (Vascular) Tissue PLANT STRUCTURE

2. Remember… Organisms are made up of: – Organ Systems – Organs – Tissues – Cells Plants are made up of: Organ Systems Organs: Roots, Stems, Leaves Tissues: Dermal, Vascular, Ground, Meristematic Cells: epidermal cells, tracheids, vessel elements, sieve tube elements, companion cells, parenchyma, collenchyma, sclerenchyma,

3. Concept Map include includes Section 23-1 Plant Tissues Dermal tissue Meristematic tissue Vascular tissue Ground tissue Epidermal cells XylemPhloem Parenchyma cells Collenchyma cells Schlerenchyma cells Tracheids Vessel elements Sieve tube elements Companion cells

4. PLANT TISSUE SYSTEMS (4) A) MERISTEMATIC  Source of new growth for the entire life of the plant Primary Growth  plants grow taller and deeper – Only in tips of roots & shoots – Apical meristem  “the bud” Secondary Growth  plants grow wider – Lateral Meristem tissue – (Also known as: vascular or cork cambium)

5. PLANT TISSUES cont. B) DERMAL TISSUE  The outer covering of the plant, “the skin” – May have waxy covering to prevent water loss C) VASCULAR TISSUE  transports fluids & nutrients throughout the plant, “the bloodstream” – Xylem  transports water – Phloem  transports food (sugars made) D) GROUND TISSUE  everything else

6. 3 Plant Organs Roots Stems Leaves

7. ROOTS FUNCTION 1. Absorbs water & dissolved nutrients from soil 2. Anchors plant & prevents erosion TYPES: 1. Taproots  long & thick, 2. Fibrous roots  thin & branching

8. ROOTS cont. STRUCTURE (by tissue) & TRANSPORT 1. Outer epidermal layer a. covered by tiny root hairs – more S.A. b. contain active transport proteins in their cell membranes to pump minerals from soil into plant. c. water follows by osmosis

9. ROOT STRUCTURE cont. 2. Large layer of Ground tissue a. spongy cortex b. endodermis encloses vascular tissue i. cells are surrounded by Casparian strips - waterproof barriers that force water to go through cells, not around. - Keep flow one way (osmosis) 3. Central Vascular cylinder a. water moves into the xylem b. because it cannot go backward, the only place to go is up the stem i. “Root Pressure”

12. STEMS FUNCTION 1. Support; hold leaves up in the sunlight 2. Transport substances between roots & leaves TRANSPORT 1. Capillary Action a. water moves by cohesion from roots b. 1 way 2. Nutrients are transported through stem a. in phloem b. in 2 directions

13. LEAVES FUNCTION 1. Site of Photosynthesis STRUCTURE 1. epidermis is covered by cuticle a. reduce evaporation 2. Mesophyll – specialized ground tissue a. lots of chloroplasts b. where photosynthesis occurs 3. Veins of xylem & phloem branch

14. LEAVES cont. SPECIAL STRUCTURES 1. Stomata  exterior openings on underside of leaf. Site of gas exchange (pores) a. O 2 out b. CO 2 in c. water vapor out 2. Guard cells  surround and control stomata openings

15. LEAVES cont. TRANSPORT 1. Water escapes through stomata a. process of transpiration (evaporation) b. as water exits, more is drawn up through stem from roots 2. Stomata open and close to prevent excessive water loss.

17. Shoots and Roots

18. Stem