Plant Structure and Function Chapter 25 Plant Structure and Function Section 1: The Vascular Plant Body Section 2: Transport in Plants 1

The Vascular Plant Body Section 1 The Vascular Plant Body Objectives: Identify the three kinds of tissues in a vascular plant's body, and state the function of each. Compare the structures of different types of roots, stems, and leaves. Relate the structures of roots, stems, and leaves to their functions. 2

The Vascular Plant Body Section 1 The Vascular Plant Body Tissues Vascular Plant Body A vascular plant’s body contains three kinds of tissues—dermal tissue, ground tissue, and vascular tissue. Dermal Tissue Dermal tissue covers a plant. A thin layer of epidermis covers nonwoody parts. Several layers of cork cover woody parts. Ground Tissue Ground tissue is specialized for photosynthesis in leaves and for storage and support in stems and roots. 3

The Vascular Plant Body Section 1 The Vascular Plant Body Vascular Tissues Vascular Tissues Vascular tissue conducts water, minerals, and organic compounds throughout the plant. Xylem Xylem contains vessels, which are made up of cells that conduct water only after they lose their cytoplasm. Water flows between cells through pits and perforations in their cell walls. Phloem Phloem contains sieve tubes, which are made up of cells that are still living. Substances pass between the cells through pores. 4

The Vascular Plant Body Section 1 The Vascular Plant Body Roots Roots Roots have a central core of vascular tissue that is surrounded by ground tissue and epidermal tissue. Root hairs on root tips increase the surface area available for absorption. 5

The Vascular Plant Body Section 1 The Vascular Plant Body Stems Nonwoody Stems Nonwoody stems contains bundles of xylem and phloem embedded in ground tissue. Woody Stems Woody stems have an inner core of xylem surrounded by a cylinder of phloem. 6

The Vascular Plant Body Section 1 The Vascular Plant Body Leaves Leaves Leaves are a mass of ground tissue and vascular tissue covered by epidermis. The ground tissue cells conduct photosynthesis. Gases are exchanged through the stomata in the epidermis. 7

Transport in Plants Objectives: Section 2 Transport in Plants Objectives: Relate transpiration to the movement of water up a plant. Describe how guard cells regulate the rate of transpiration. Recognize several distinguishing features of sugar maple trees. Describe the process of translocation in a plant. 8

Transport in Plants Movement of Water Section 2 Transport in Plants Movement of Water Transpiration Transpiration, the loss of water from a plant’s leaves, creates a pull that draws water up through xylem from roots to leaves. Guard Cells and Transpiration Guard cells control water loss by closing a plant’s stomata when water is scarce. Thus, they also regulate the rate of transpiration. 9

Transport in Plants Movement of Organic Compounds Section 2 Transport in Plants Movement of Organic Compounds Translocation Organic compounds are pushed through the phloem from a source to a sink in a process called translocation. 10