 Chapter 24 The Root: Structure and Development1Chapter 24: The Root: Structure and DevelopmentMultiple-Choice Questions1. Introduction; p. 558; easy; ans; bWhen a seed germinates, the __________ is the first structure to emerge.a. plumuleb. rootc. hypocotyld. epicotyle. cotyledon2. Introduction; p. 558; easy; ans: dThe two primary functions of roots are:a. conduction and protection.b. storage and conduction.c. anchorage and storage.d. anchorage and absorption.e. anchorage and conduction.3. Introduction; pp. 558-559; moderate; ans: eWhich of the following statements concerning roots is FALSE?a. Some roots produce buds.b. Some roots store food.c. Some roots synthesize nicotine.d. Some roots synthesize cytokinins.e. Some roots contain an internal rhizosphere.4. Introduction; pp. 558-559; easy; ans: bThe rhizosphere is the volume of:a. nitrogen-fixing bacteria surrounding the root.b. soil around the root.c. mucilage secreted by the root.d. root hairs plus mucilage.e. rootcap cells released from the root.5. Root Systems; p. 559; moderate; ans: dIn gymnosperms and eudicots, the primary root is called the:a. fibrous root.b. prop root.c. lateral root.d. taproot.e. branch root. Chapter 24 The Root: Structure and Development6. Root Systems; p. 559; moderate; ans: bWhich of the following statements about monocot roots is FALSE?a. The root system is generally shallower than in eudicots.b. The main root system has one prominent root. c. The roots form a fibrous root system.d. The main root system develops from roots arising from the stem.e. The primary root is short-lived.7. Root Systems; p. 559; easy; ans: aWhich of the following statements about feeder roots is FALSE?a. They are usually found in the lower 15 centimeters of soil.b. They are actively engaged in water uptake.c. They are actively engaged in nutrient uptake.d. They can be heavily infected with mycorrhizal fungi.e. They are also called fine roots.8. Root Systems; p. 560; difficult; ans: eAfter you transplant a shrub, which of the following is the more effective next step you should do to increase the chances that the shrub will survive?a. Add fertilizer.b. Add weed killers.c. Cut back the fine roots.d. Cut back the lateral roots.e. Cut back the shoot.9. Origin and Growth of Primary Tissues; pp. 560-561; moderate; ans: cWhich of the following statements about the rootcap is FALSE?a. It secretes mucilage.b. Its peripheral cells are released as it grows through the soil.c. Its peripheral cells are not replaced. d. It helps the root penetrate the soil.e. It protects the root apical meristem.10. Origin and Growth of Primary Tissues; pp. 561-562; moderate; ans: eWhich of the following statements about border cells is FALSE?a. They are the peripheral cells of the root cap. b. They are programmed to separate from the root cap and from each other. c. They remain alive in the soil as individual cells. d. They protect the apical meristem from infection.e. They produce a similar array of proteins during their lifetime.Chapter 24 The Root: Structure and Development11. Origin and Growth of Primary Tissues; p. 562; easy; ans: dGravity- and water-potential gradients are perceived by the:a. root apical meristem.b. root hairs.c. columella. d. lateral rootcap.e. border cells.12. Origin and Growth of Primary Tissues; p. 562; moderate; ans: bThe promeristem of the root:a. is composed of initials but not derivatives.b. is the most distal part of the apical meristem.c. is the most determined part of the apical meristem.d. is characterized by few-sided cells with nondense cytoplasm.e. is composed of relatively large cells with small nuclei.13. Origin and Growth of Primary Tissues; p. 562; difficult; ans: dIn a “closed type” of root apical organization, the:a. apical meristem lacks derivatives.b. cortex and vascular cylinder each have their own initials, but the rootcap and epidermis do not.c. cortex and rootcap each have their own initials, but the vascular cylinder and epidermis do not.d. rootcap, vascular cylinder, and cortex each have their own initials.e. rootcap, vascular cylinder, and cortex have common initials.14. Origin and Growth of Primary Tissues; pp. 562-563; difficult; ans: aWhich of the following statements about the quiescent center is FALSE?a. It is located a short distance behind the apical meristem.b. It may play an important role in the organization and development of the root.c. It is a region that was mitotically active early in root development.d. It is a relatively inactive region of the mature root apical meristem.e. Quiescent centers isolated from maize can form whole roots in culture without first forming callus.15. Origin and Growth of Primary Tissues; pp. 563-564; moderate; ans: cThe sequence of regions in a growing root, beginning immediately behind the rootcap, is:a. elongation, maturation, cell division.b. cell division, maturation, elongation.c. cell division, elongation, maturation.d. elongation, cell division, maturation.e. maturation, elongation, cell division. Chapter 24 The Root: Structure and Development16. Origin and Growth of Primary Tissues; p. 564; moderate; ans: cRoot hairs are produced in the:a. region of cell division.b. region of elongation.c. region of maturation.d. quiescent center.e. area between the regions of cell division and elongation.17. Origin and Growth of Primary Tissues; p. 564; moderate; ans: bProtophloem and protoxylem mature in the:a. region of cell division.b. region of elongation.c. region of maturation.d. quiescent center.e. area between the regions of cell division and elongation.18. Primary Structure; p. 565; easy; ans: eThe ______ occupies the greatest area of the primary root.a. epidermis b. xylemc. phloemd. pericyclee. cortex19. Primary Structure; p. 565; easy; ans: aAerenchyma is found in the:a. cortex.b. pericycle.c. phloem.d. xylem. e. epidermis. 20. Primary Structure; p. 565; moderate; ans: cSubstances moving through the root cortex: a. follow a symplastic pathway only.b. follow an apoplastic pathway only.c. follow both symplastic and apoplastic pathways.d. are unable to travel via cell walls.e. are unable to pass through plasmodesmata.Chapter 24 The Root: Structure and Development21. Primary Structure; p. 565; easy; ans: dThe innermost layer of the cortex is the:a. pericycle.b. xylem.c. epidermis.d. endodermis.e. pith.22. Primary Structure; pp. 565-566; moderate; ans: bWhich of the following statements about Casparian strips is FALSE?a. They