5. Formation of the Embryo; p. 499; moderate; ans: T Regulatory genes affect the apical-basal pattern of embryonic development in Arabidopsis . 6. The Mature Embryo and Seed; p. 503; moderate; ans: F The first bud of the embryonic shoot of angiosperms is called the epicotyl. 7. The Mature Embryo and Seed; p. 503; moderate; ans: T Seeds with large cotyledons typically have little or no endosperm. 8. The Mature Embryo and Seed; p. 504; easy; ans: F The coleoptile and coleorhiza are typically found in monocots, eudicots, and magnoliids. 9. Requirements for Seed Germination; pp. 504–505; moderate; ans: T Before a seed can germinate, it must first imbibe water. 10. Requirements for Seed Germination; p. 505; moderate; ans: T Before the seed coat ruptures during germination, glucose breakdown may be entirely anaerobic. 11. Requirements for Seed Germination; p. 505; moderate; ans: F The optimal temperature range for seed germination of many species is 0 o to 5 o C. 12. Requirements for Seed Germination; p. 505; easy; ans: T A dormant seed will not germinate even when external conditions are favorable. 13. Requirements for Seed Germination; p. 505; difficult; ans: F In temperate regions, after-ripening ensures that seeds will germinate in the fall rather than in the spring. 14. Requirements for Seed Germination; p. 505; moderate; ans: F In castor bean ( Ricinus communis ), the epicotyl forms the hook. 15. From Embryo to Adult Plant; p. 507; easy; ans: T In hypogeous germination, the cotyledons remain in the soil. Essay Questions 1. Introduction; p. 497; moderate Why is it important to study mutations that disrupt the basic patterns of development in plants? 2. Formation of the Embryo; p. 497; moderate Discuss the concept of polarity as it pertains to angiosperm embryogenesis. 3. Formation of the Embryo; p. 498; moderate Explain the difference between the proembryo and the embryo proper.

Chapter 22 Early Development of the Plant Body 9 4. Formation of the Embryo; p. 498; moderate Define the term “primary meristem.” Name the three primary meristems, and name the tissue(s) into which each develops. 5. Formation of the Embryo; p. 498; moderate List the principal stages of embryonic development in angiosperms, and describe the appearance of the embryo at each stage. 6. Formation of the Embryo; p. 498; moderate How is an apical meristem different from a primary meristem? 7. Formation of the Embryo; pp. 498–499; moderate Discuss the role(s) of the suspensor during embryogenesis in angiosperms. 8. Formation of the Embryo; p. 499; difficult The Arabidopsis gnom mutant (shown in Figure 22-6) consists of only a stem-like structure containing an epidermis, ground tissue, and vascular tissue. What typical embryonic parts is this seedling missing? What might be the function of the gnom gene in seedling development? 9. Formation of the Embryo; p. 499; difficult In flowering plants, how does the development of the embryo affect the development of the suspensor? Give evidence to support your answer.