Chapter 27: Seedless Plants

52. Identify and briefly describe the two phyla of seedless vascular plants. Include one or two representatives of each phylum.

The main points are summarized in Table 27-2 in the text

57. In algae, gametangia are generally unicellular

True

61. An archegoniophore is found in certain liverworts.

True

65. A(n) sorus is a cluster of sporangia.

True

31. The structure in the accompanying figure labeled as 4 is:

a. haploid.

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 70. hornworts

a. Anthocerophyta

34. According to the fossil record, the oldest vascular plants are placed in which phylum?

a. Rhyniophyta

12. What is the male sexual structure that produces sperm in plants?

a. antheridium

39. The leafy fern that you might have as a house plant is the ____ generation.

a. diploid sporophyte

41. The sori of most ferns are found on which part of the plant?

a. fronds

35. The oldest known megafossils of early vascular plants may be characterized as:

a. possessing dichotomously branched stems without leaves or roots.

40. The gametophyte generation of ferns is the:

a. prothallus.

46. What do ferns lack?

a. seeds

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 72. mosses

b. Bryophyta

48. Which of the following is heterosporous?

b. spike moss

10. Refer to the accompanying figure. At what point of this life cycle does fertilization occur?

b. 4

36. ____ are small leaves with a single vascular strand.

b. Microphylls

5. The first plants evolved rapidly during which time period?

b. Silurian

18. Why are mosses and liverworts limited in size?

b. They lack vascular tissues.

9. Alternation of generations in plants refers to the alternation of:

b. diploid and haploid stages.

47. Which of the following is a vascular plant?

b. fern

30. The ____ generation is dominant in mosses, as it can live independently.

b. haploid gametophyte

43. Which plant has a jointed hollow stem with reduced megaphylls?

b. horsetail

45. Heterospory is believed to have led to the evolution of:

b. seeds.

17. Which vascular tissue is responsible for conducting water and dissolved minerals in plants?

b. xylem

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 71. liverworts

c. Hepaticophyta

50. The ____ of horsetails and club moss consists of several stalked, umbrella-like structures that produce sporangia.

c. strobilus

6. Which is a differentiating characteristic of land plants from green algae?

c. Land plants have a waxy cuticle.

33. The life cycle in the accompanying figure could represent which organism?

c. a club moss

26. Which is the gametophyte form of most liverworts?

c. a thallus

7. Plants are believed to have evolved from which group of algae?

c. charophytes

1. Which is a characteristic shared between green algae and plants?

c. chlorophylls a and b in plastids

16. In plants, the fertilized egg develops into a multicellular ____ (young plant) within a female gametangium.

c. embryo

4. What is the structure labeled as A in the accompanying figure?

c. gametangium of an alga

19. Some liverworts reproduce asexually by forming tiny balls of tissue called:

c. gemmae.

38. Which two plants of the Carboniferous period contributed to the formation of today's coal deposits?

c. horsetails and club mosses

13. A key step in the evolution of vascular plants was the ability to produce ____, a strengthening polymer in the walls of cells that function for support and conduction

c. lignin

21. The gametophyte is the dominant stage in the life cycle for which of the following plant groups?

c. liverworts

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 76. club mosses

d. Lycopodiophyta

49. Microsporocytes divide by ____ to form ____.

d. meiosis; microspores

20. A bryophyte having a single large chloroplast in each cell belongs to which phylum?

d. Anthocerophyta

25. Which is the most economically important bryophyte?

d. Sphagnum.

14. Which group of plants are the most recent to evolve?

d. angiosperms

37. Microphylls is a structure that can only be found in:

d. club mosses.

3. What is the structure labeled as 1 in the accompanying figure?

d. gamete

44. Many seedless plants produce spores of one morphological type, which is referred to as:

d. homospory.

22. What is the most ancient group of plants alive today?

d. liverworts

28. When a moss spore lands in a suitable spot, it germinates and grows into a filament of cells called a:

d. protonema.

23. After sexual reproduction in a moss, the ____ grows out of the gametophyte.

d. sporophyte

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 73. ferns

e. Pteridophyta

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 74. whisk ferns

e. Pteridophyta

Match the plant phylum with the appropriate word or phrase. a. Anthocerophyta b. Bryophyta c. Hepaticophyta d. Lycopodiophyta e. Pteridophyta 75. horsetails

e. Pteridophyta

11. Refer to the accompanying figure. At what point is there potential to undergo mitosis to become a gametophyte?

e. 9

27. How are the sperm of moss transported to the archegonia?

e. Both insects and water

24. How do mosses help prevent soil erosion?

e. Mosses are packed in dense colonies, holding soil together.

42. Which statement about whisk ferns is FALSE?

e. They lack true stems.

2. Modern botanists think that all plants evolved from a common ancestor that was an ancient green algae. What is the best explanation for this hypothesis?

e. They share many biochemical and metabolic traits.

15. What are the multicellular sex organs in plants?

e. gametangia

32. Refer to the accompanying figure. Which statement about label 1 is FALSE?

e.It is part of the sporophyte generation.

69. If you were a paleontologist studying clams, you would have an easier research project than if you were studying early plants. Why? Include in your discussion the term megafossils.

Concepts to Consider: Megafossils are the fossilized parts of a plant or animal. Because the earliest plants were typically softer than mollusks, fossils are harder to find and identify (although thousands have been identified and studied); spores occur in the fossil record earlier than megafossils found to date, so older plant fossils may be waiting to be discovered. Clams are aquatic and are more likely to be covered by sediments before decomposing, and their shell is a tough calcareous material and so does not decompose readily.

68. Describe alternation of generations. Include in your discussion the following terms: gametophyte, sporophyte, diploid, haploid, dominant form, meiosis, and fertilization.

Concepts to Consider: Plants alternate between a haploid gametophyte and a diploid sporophyte. The dominant form varies; the gametophyte is dominant in the mosses, and the sporophyte is dominant in the ferns, gymnosperms, and angiosperms

67. Discuss adaptations for terrestrial life seen in land plants.

Concepts to Consider: Stomata to allow carbon dioxide to enter the leaf; a waxy cuticle to reduce water loss; gametangia with sterile cells to protect the reproductive cells; lessened reliance on water for reproduction.

51. Prepare a table that lists the features that distinguish bryophytes from green algae and from other plants.

Distinguishing features shared by plants include 1) multicellular embryos, 2) multicellular gametangia, 3) a waxy cuticle, 4) stomata, 5), a clearly defined alternation of generations, and 6) producing spores only by meiosis instead of by either meiosis or mitosis.

62. A gemma is a(n) sexual reproductive structure produced by certain liverworts.

False - asexual

66. If a plant produces microspores and megaspores, then by definition, it is homosporous

False - heterosporous

59. Mosses have stems, roots, and leaves.

False - lack, do not have

56. In plants, sporogenous cells divide by mitosis to form spores.

False - meiosis

60. After a moss spore germinates it forms a(n) prothallus.

False - protonema

55. Xylem is a vascular tissue that conducts dissolved sugars.

False - water and dissolved minerals

53. Diagram and label the life cycle of a fern. Be sure to identify the gametophyte and sporophyte generations.

The diagram should resemble Figure 27-16 in the text.

64. Club mosses belong to the phylum Bryophyta.

False - Lycopodiophyta

63. Microphylls evolved from stem branches.

False - Megaphylls

58. Each archegonium produces many eggs

False - a single egg

54. Diagram the evolution of microphylls and megaphylls.

These processes are diagrammed in Figure 27-12 in the text.

8. What is the purpose of the waxy cuticle in plants?

a. It prevents desiccation.