Plant Structure Function I The Vascular Plant Body

Plant Structure & Function I. The Vascular Plant Body Tissues: dermal tissue – the protective outer layer of a plant; forms the epidermis where gas is exchanged through the stomata ground tissue – the inside of the non-woody parts; conducts photosynthesis vascular tissue – contains xylem (transports water & nutrients) and phloem (transports organic compounds - food)

Plant Tissues

Roots: root hairs – an extension of the epidermis of a root that increases the root’s surface area for absorption n root cap – the protective layer of cells that covers the tip of a root n

Root Hairs and Root Cap

Leaves: n n n n lamina – (blade) large flatten portion of leaf cuticle – outer waxy coat that covers the upper and lower epidermis of the leaf; protects it from damage and drying out apex – tip of blade base – bottom of blade petiole – a stalk that attaches the leaf to the stem stipules – small paired appendages at the base of the petiole midrib – the central rib or vein of a leaf veins – vascular structures containing xylem & phloem that run throughout the leaf

Parts of a Leaf Apex Lamina Vein Margin Midrib Petiole (leaf stalk) Stipules Axil Base

Simple vs. Compound Leaves Node

Internal Structure of a Leaf

II. Transport in Plants A. Movement of Water 1. Xylem – transports water and nutrients through capillary action (adhesion) 2. Transpiration – the loss of water vapor through the stomata of a leaf

B. Movement of Organic Compounds 1. Phloem – transports organic compounds (sugars=food) 2. Translocation – the movement of organic compounds through a plant from a source to a sink (occurs b/c of the pressure flow model) H 2 O Source Sink Sugar

Stems: non-woody stems – flexible , usually green stems; herbaceous plants have non-woody stems n woody stems – covered by cork which protects them from physical damage and water loss bark – made of layers of cork and phloem n

Bark on Woody Stems Leaves connect to the stems of plants at the. . .