Roots Stems Leaves Tissues BSC 2011 L Review

Roots, Stems, Leaves, Tissues BSC 2011 L

Review of difference between monocots and dicots

Organization of Flowering Plants 3 vegetative organs that don’t have to do with reproduction: Root – anchor the plant, and absorb water and minerals Stem – supports leaves Leaves – carry on photosynthesis 3 major tissues of vegetative organs: Dermal tissue Ground tissues Outer protective coating of organ Interior of plant organ Vascular tissue Xylem (transports water) and phloem (transports sugars) Transports, supports

Ground Tissue 3 cell types according to cell wall structure Parenchyma Large vacuoles Important roles: Photosynthesis in leaves Storage of proteins in fruits Storage of starch in roots Collenchyma Generally elongated Provide support to leaf petioles, nonwoody stems, growing organs Sclerenchyma Thickened cell walls for support Undergo programmed cell death often and offer support then (in wood and bark)

Growth Primary Growth Increases length of plant Secondary Growth Increases girth of plant

Growth - Apical Meristem Located at terminal end of stem, branches, root tip Continuous growth

Growth – Lateral Meristem The roots and stems of some Eudicots develop secondary plant body – tissues referred to as wood and bark 2 Lateral Meristems Vascular Cambium – supplies cells of secondary xylem and phloem which eventually become wood and bark Cork cambium – waxy protective cells that become bark

Root System Eudicot Root Monocot Root

Roots Note location of: Root cap Zone of cell division Zone of elongation Zone of maturation

Root Diversity Types of roots Taproots – main root is larger and often serves as food storage Fibrous roots – all of the roots approximately same size

Stems Monocots Usually herbaceous (non-woody) Dicots Some are herbaceous Trees - woody

Stems Dicot Monocot

Stem Diversity Other examples: Rhizomes – horizontal underground stems that can give rise to new shoots Bamboo Bulbs – stems with many fleshy layers of leaves that store nutrients Lilies, onions

Anatomy of woody stems – only in dicots Primary growth Apical meristem within termnial bud is active Secondary growth Vascular cambium is active Produces new xylem and phloem each year Build-up of this every year is called wood

Woody Stems

Dicot Leaves Monocot

Leaves Petiole