Plant Tissues and The Vascular System Interest Grabber Let the Water Flow Recall that vascular tissue transports water and nutrients throughout a plant. Imagine that you and your partner have been asked by a bioengineering firm to design a mechanism that can be used by plants to transport food, water, and essential nutrients to a height of 92 meters. Section What plant characteristics must you consider in your design? 2. What environmental conditions must you take into account for your design to be functional? 3. Outline the major characteristics of your design.

Plant Tissues and The Vascular System Section Outline Specialized Tissues in Plants A.Structure of Seed Plants 1.Roots 2.Stems 3.Leaves 4.Tissue Systems B.Meristematic Tissue C.Dermal Tissue D.Vascular Tissue 1.Xylem 2.Phloem E.Ground Tissue Section 23-1

Plant Tissues and The Vascular System KEY CONCEPT Plants have specialized cells and tissue systems.

Plant Tissues and The Vascular System Plant tissues are made of three basic cell types. Parenchyma cells are the most common plant cell type. –store starch, oils and water –help heal wounds to the plant –have thin flexible walls

Plant Tissues and The Vascular System –they are strong and flexible. –celery strings are strands of collenchyma. –they have unevenly thick cell walls. Collenchyma cells provide support to a growing plant.

Plant Tissues and The Vascular System –second cell wall hardened by lignin –die when they reach maturity –used by humans to make linen and rope Sclerenchyma cells are the strongest plant cell type.

Plant Tissues and The Vascular System Plant organs are made of three tissue systems. Dermal tissue covers the outside of a plant. –protects the plant –secretes cuticle of leaves –forms outer bark of trees

Plant Tissues and The Vascular System –provides support –stores materials in roots and stems –most commonly made of parenchyma Ground tissue is found inside a plant.

Plant Tissues and The Vascular System stem leaf root –two networks of hollow tubes –xylem transports water and minerals –phloem transports photosynthetic products Vascular tissue transports water, minerals and organic compounds.

Plant Tissues and The Vascular System 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

Plant Tissues and The Vascular System Dermal tissue Vascular tissue Ground tissue Stem Root Leaf Section 23-1 Figure 23–1 Root, Stem, and Leaf Tissues

Plant Tissues and The Vascular System Interest Grabber Stem Study Imagine walking through a botanical garden. You probably would see many different kinds of plants, such as small and large trees, flowering plants, and cacti. Section How do the stems of trees, flowering plants, and cacti differ? 2. How are the stems of these plants similar?

Plant Tissues and The Vascular System Section Outline Section 23-3 Stems A. Stem Structure and Function B. Monocot and Dicot Stems 1. Monocot Stems 2. Dicot Stems C. Primary Growth of Stems D. Secondary Growth of Stems 1. Formation of the Vascular Cambium 2. Formation of Wood 3. Formation of Bark

Plant Tissues and The Vascular System Comparing Primary and Secondary Growth of Stems Characteristics Where It Occurs Effect on Plant How It Is Produced Characteristics Where It Occurs Effect on Plant How It Is Produced Primary Growth Secondary Growth Section 23-3 Compare/Contrast Table At ends of plants Increases plant length By cell division in the apical meristem In stem Increases stem width By cell division in meristems other than the apical meristem

Plant Tissues and The Vascular System Section 23-3 A.Vascular cambium appears B.Secondary growth continues C.Mature stem develops Epidermis Cortex Primary phloem Vascular cambium Primary xylem Pith Secondary phloem Secondary xylem Cork Cork cambium Primary phloem Secondary phloem Secondary xylem Primary xylem Bark Wood Figure 23–14 Secondary Growth in Stems

Plant Tissues and The Vascular System Section 23-3 WoodBark Cork Cork Cambium Phloem Vascular Cambium Xylem: Sapwood Xylem: Heartwood Figure 23–15 Layers of a Tree Trunk Contains old, nonfunctioning xylem that helps support the tree Contains active xylem that transports water and minerals Produces new xylem and phloem, which increase the width of the stem Transports sugars produced by photosynthesis Produces protective layer of cork Contains old, nonfunctioning phloem that protects the tree

Plant Tissues and The Vascular System KEY CONCEPT The vascular system allows for the transport of water, minerals, and sugars.

Plant Tissues and The Vascular System Water and dissolved minerals move through xylem. Xylem contains specialized cells. –vessel elements are short and wide –tracheid cells are long and narrow –xylem cells die at maturity vessel element tracheid

Plant Tissues and The Vascular System –Plants passively transport water through the xylem. –Cohesion is the tendency of water molecules to bond with each other. The cohesion-tension theory explains water movement. –Adhesion is the tendency of water molecules to bond with other substances.

Plant Tissues and The Vascular System –absorption occurs at roots Water travels from roots to the top of trees. –cohesion and adhesion in xylem –transpiration at leaves

Plant Tissues and The Vascular System –water vapor exits leaf stomata –helps pull water to the top branches Transpiration is the loss of water vapor through leaves.

Plant Tissues and The Vascular System Phloem carries sugars from photosynthesis throughout the plant. Phloem contains specialized cells. –sieve tube elements have holes at ends –companion cells help sieve tube elements –unlike xylem, phloem tissue is alive

Plant Tissues and The Vascular System –plants actively transport sugar from the source –sugar flows to the sink due to pressure differences sugars phloemxylem water Sugars move from their source, such as photosynthesizing leaves, into the phloem. 1 The sugars move into the sink, such as root or fruit, where the are stored. 3 Water moves from the xylem into the phloem by osmosis, due to the higher concentration of the sugars in the phloem. The water flow helps move sugars through the phloem. 2 The Pressure-flow model explains sugar movement.