Chapter 38

Summary		Questions		Media Resources
38.1 Meristems elaborate the plant body plan after germination.
• A plant body is basically an axis that includes two parts: root and shoot-with associated leaves. There are three basic types of tissues in plants arising from meristems or embryonic cells: ground tissue, epidermis, and vascular tissue.		1.  What are the three major tissue systems in plants? What are their functions?		•Stem Tip Structure •Primary Meristem Structure •Plant Body Organization •Meristems
38.2 Plants have three basic tissues, each composed of several cell types.
• Epidermis forms an outer protective covering for the plant. • Ground tissue supports the plant and stores food and water. • Vascular tissue conducts water, carbohydrates, and dissolved minerals to different parts of the plant. Xylem conducts water and minerals from the roots to shoots and leaves, and phloem conducts food molecules from sources to all parts of the plant.		2.  What is the function of xylem? How do primary and secondary xylem differ in origin? What are the two types of conducting cells within xylem? 3.  What is the function of phloem?		•Vascular System of Plants •Ground Tissue •Dermal Tissue •Vascular Tissue •Activity: Vascular Tissue
38.3 Root cells differentiate as they become distanced from the dividing root apical meristem.
• Roots have four growth zones: the root cap, zone of cell division, zone of elongation, and zone of maturation. • Some plants have modified roots, adapted for photosynthesis, food or water storage, structural support, or parasitism.		4.  Compare monocot and dicot roots. How does the arrangement of the tissues differ? 5.  How are lateral branches of roots formed?		•Dicot Root Structure •Roots
38.4 Stems are the backbone of the shoot, transporting nutrients and supporting the aerial plant organs.
• Plants branch by means of buds derived from the primary apical meristem. They are found in the junction between the leaf and the stem. • The vascular cambium is a cylinder of dividing cells found in both roots and shoots of gymnosperms and dicots. As a result of their activity, the girth of a plant increases.		6.  What types of cells are produced when the vascular cambium divides outwardly, inwardly, or laterally? 7.  Why don't monocots have secondary growth?		•Dicot Stem Structure A •Dicot Stem Structure B •Dicot Stem Structure C •Secondary Growth •Herbaceous Dicot Stem Anatomy •Girth Increase in Woody Dicots •Stems •Cambia •Activity: Cambium
38.5 Leaves are adapted to support basic plant functions.
• Leaves emerge as bulges on the meristem in a variety of patterns, but most form a spiral around the stem. The bulge lengthens and loses its radial symmetry as it flattens. • Photosynthesis occurs in the ground tissue system which is called mesophyll in the leaf. Vascular tissue forms the venation patterns in the leaves, serving as the endpoint for water conduction and often the starting point for the transport of photosynthetically produced sugars.		8.  How do simple and compound leaves differ from each other? Name and describe the three common types of leaf growth patterns.		•Plant Anatomy •Leaf Structure •Leaves •Stoma • Abscission Zone

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