<p> ANSWERS</p><p>15. Structures D, E, F, G, H, I, J, K, and L are haploid. 16. Student answers might include that structure A is a sporophyte (diploid). It produces spores, and does not undergo photosynthesis. Structure B is a gametophyte. It produces gametes, undergoes photosynthesis, and has rhizoids (haploid). 17. Structure M is formed by fertilization; it is called a zygote. 18. Structures F and G are different kinds of gametophytes. Structure F is a female gametophyte, which has archegonia. Structure G is a male gametophyte, which has antheridia. 19. Spores (structures D) are formed by meiosis. 20. Structures F, G, H, I, and J are part of the gametophyte stage of a fern. 21. Structures C, which are spores, are released from structure B, which is a sporangium. 22. Structures G and J produce different kinds of gametes. Structure G, an archegonium, produces eggs. Structure J, an antheridium, produces sperm. 23. Structures C will become gametophytes. 24. Structure E, the mature sporophyte, grows from structure F, the gametophyte. 25. A corn seed has one seed leaf. 26. The maple leaf is a dicot because it has branching veins. 27. The vascular bundles are scattered throughout the stem. 28. The iris is a monocot because it has six floral parts, which is a multiple of three. 29. A taproot will grow from a bean seed. 30. the style 31. J, the petal 32. Structures labeled F or G are male parts; A, B, C, and D (or E) are female parts. 33. F, the anther 34. D, the stigma 35. a pollen tube 36. There are eight nuclei in the embryo sac. They arose from a single haploid cell, which underwent mitosis. 37. A seed coat develops after fertilization. 38. The volume of the endosperm increases. 39. Because flowers are attractive to animals, the pollen in Figure 24–5 likely will be dispersed by an animal feeding on the flower’s pollen or nectar. 40. The structures labeled A are pollen grains, and the structures labeled E, F, and G illustrate the interaction of the pollen grains with ovules. The role of the pollen grains is to fertilize the ovules. 41. Structure C is a diploid cell. 42. Structure D is the female gametophyte. The illustration shows one egg, whereas in a real plant each gametophyte contains more than one egg cell. 43. Structure H is a zygote, produced by fertilization. 44. The seed coat encloses structures I (the gametophyte) and J (the embryo). The seed coat arises from parts of the ovule.</p>