Chapter 6
Plant Organs: Roots
CHAPTER OUTLINE
Root structure and function
Roots provide anchorage, absorption, conduction, and storage
Roots possess a root cap and root hairs
Roots of herbaceous eudicot and monocots
CHAPTER OBJECTIVES
1. Describe the functions of roots and describe two features of roots that shoots lack.
2. Contrast the structure of a primary eudicot root and a monocot root, and describe the functions
LECTURE OUTLINE
I. What are the two types of root systems?
A. Compare the taproot system and the fibrous root system.
B. What is an adventitious root? What root system has adventitious roots?
II. What are the three general functions of roots?
IV. Describe the structure of a typical eudicot root.
A. Why does the root epidermis lack a cuticle?
B. What kind of tissue comprises the cortex?
1. Where is the cortex located?
C. What is the function of the endodermis?
1. Where is the endodermic located?
2. What is the Casparian strip?
D. What is the single layer of cells just inside the endodermis? What is its function?
E. What tissues are at the center of most eudicot roots? What is the region called?
1. What shape does the xylem take?
2. Where is the phloem located in relation to the xylem?
V. Describe how the structure of a typical monocot root differs from a eudicot root.
A. How are the vascular tissues arranged?
B. What tissue is in the center of the root?
C. Do most monocot roots have a vascular cambium?
D. Can monocot roots produce secondary growth?
VI. What specializations are found in roots adapted for unusual functions?
A. What are prop roots?
KEY TERMS
adventitious, p. 112
apical meristem, p. 115
apoplast, p. 118
fibrous root system, p. 112
mycorrhizae, p. 123
nodules, p. 125
root graft, p. 123
root hair, p. 115
selective breeding, p. 117
TEACHING TIPS
1. Save an hour of lab time to cook and sample a variety of root foods. Select things that may be
new to at least some of the students. Many people have never eaten parsnips, turnips, or
2. Do a “dissection” of a carrot root to compare the cortex and the stele. Have students cut a carrot
in cross-sections to make carrot disks. Ask students to carefully eat the outside portion of the
3. Three–dimensional models are useful to help students comprehend the arrangement of tissues in