1. CHAPTER 17 Plants, Fungi, and the Colonization of Land
Modules 17.1 – 17.3

2. Plants and Fungi—A Beneficial Partnership
Mutually beneficial associations of plant roots and fungi are common
These associations are called mycorrhizae
They may have enabled plants to colonize land

3. Citrus growers face a dilemma
They use chemicals to control disease-causing fungi
But these also kill beneficial mycorrhizae

4. Plants are multicellular photosynthetic eukaryotes
17.1 What is a plant?
Plants are multicellular photosynthetic eukaryotes
They share many characteristics with green algae
However, plants evolved unique features as they colonized land

5. PLANT
LEAF performs photosynthesis
CUTICLE reduces water loss; STOMATA allow gas exchange
STEM supports plant (and may perform photosynthesis)
ALGA
Surrounding water supports the alga
WHOLE ALGA performs photosynthesis; absorbs water, CO2, and minerals from the water
ROOTS anchor plant; absorb water and minerals from the soil (aided by mycorrhizal fungi)
HOLDFAST anchors the alga
Figure 17.1A

6. Unlike algae, plants have vascular tissue
It transports water and nutrients throughout the plant body
It provides internal support
Figure 17.1B

7. 17.2 Plants evolved from green algae called charophyceans
PLANT EVOLUTION AND DIVERSITY
17.2 Plants evolved from green algae called charophyceans
Molecular studies indicate that green algae called charophyceans are the closest relatives of plants
Figure 17.2A, B

8. Cooksonia was one of the earliest vascular land plants
Sporangia
Figure 17.2C

9. 17.3 Plant diversity provides clues to the evolutionary history of the plant kingdom
Two main lineages arose early from ancestral plants

10. Radiation of flowering plants
CENOZOIC
Gymnosperms (e.g., conifers)
Angiosperms
Seedless vascular plants (e.g., ferns, horsetails)
Bryophytes (e.g., mosses)
Radiation of flowering plants
MESOZOIC
Charophyceans (a group of green algae)
First seed plants
Early vascular plants
PALEOZOIC
Origin of plants
Figure 17.3A

11. One lineage gave rise to bryophytes
These are plants that lack vascular tissue
Bryophytes include mosses, which grow in a low, spongy mat
Figure 17.3B

12. Vascular plants are the other ancient lineage
Ferns and seed plants were derived from early vascular plants and contain
xylem and phloem
well-developed roots
rigid stems

13. Ferns are seedless plants whose flagellated sperm require moisture to reach the egg
Figure 17.3C

14. A major step in plant evolution was the appearance of seed plants
Gymnosperms
Angiosperms
These vascular plants have pollen grains for transporting sperm
They also protect their embryos in seeds

15. Gymnosperms, such as pines, are called naked seed plants
This is because their seeds do not develop inside a protective chamber
The seeds of angiosperms, flowering plants, develop in ovaries within fruits

16. 17.4 Haploid and diploid generations alternate in plant life cycles
ALTERNATION OF GENERATIONS AND PLANT LIFE CYCLES
17.4 Haploid and diploid generations alternate in plant life cycles
The haploid gametophyte produces eggs and sperm by mitosis
The eggs and sperm unite, and the zygote develops into the diploid sporophyte
Meiosis in the sporophyte produces haploid spores, which grow into gametophytes

17. Gametophytes (male and female) n Gametes (sperm and eggs) n
Mitosis
Mitosis
Spores n
Gametes (sperm and eggs) n
HAPLOID
Meiosis
Fertilization
DIPLOID
Zygote 2n
Mitosis
Sporophyte 2n
Figure 17.4

18. 17.5 Mosses have a dominant gametophyte
Most of a mat of moss consists of gametophytes
These produce eggs and swimming sperm
The zygote stays on the gametophyte and develops into the less conspicuous sporophyte

19. Sporophytes (growing from gametophytes)5
Mitosis and development
Sperm (n) (released from their gametangium)
Spores (n) 1
Gametangium containing the egg (n) (remains within gametophyte)
Gametophytes (n)
Egg
HAPLOID
Meiosis
Fertilization
DIPLOID
Sporangium
Stalk 2 4
Zygote (2n)
Gametophyte (n) 3
Mitosis and development
Sporophytes (growing from gametophytes)
Figure 17.5

20. 17.6 Ferns, like most plants, have a dominant sporophyte
Ferns, like mosses, have swimming sperm
The fern zygote remains on the small, inconspicuous gametophyte
Here it develops into the sporophyte

21. 5 1 HAPLOID DIPLOID 2 4 3 Sperm (n) Mitosis and development Spores (n)
Gametophyte (n) (underside)
Egg (n)
HAPLOID
Fertilization
Meiosis
Sporangia
DIPLOID 2 4
Zygote (2n) 3
Mitosis and development
New sporophyte growing out of gametophyte
Sporophyte (2n)
Figure 17.6

22. 17.7 Seedless plants formed vast “coal forests”
Ferns and other seedless plants once dominated ancient forests
Their remains formed coal
Figure 17.7

23. Gymnosperms that produce cones, the conifers, largely replaced the ancient forests of seedless plants
These plants remain the dominant gymnosperms today

24. 17.8 A pine tree is a sporophyte with tiny gametophytes in its cones
Sporangia in male cones make spores that develop into male gametophytes
These are the pollen grains
Sporangia in female cones produce female gametophytes

25. 4 5 HAPLOID DIPLOID 3 1 6 2 7 Female gametophyte (n)
Haploid spore cells in ovule develop into female gametophyte, which makes egg. 5
Egg (n)
Male gametophyte (pollen) grows tube to egg and makes and releases sperm.
Sperm (n)
Male gametophyte (pollen grain)
HAPLOID
MEIOSIS
Fertilization
DIPLOID
Scale
Sporangium (2n)
Ovule
Seed coat
Zygote (2n) 3
Pollination
Embryo (2n)
HAPLOID Pollen grains (male gametophytes) (n)
Integument 1
Female cone bears ovules. 6
Zygote develops into embryo, and ovule becomes seed.
MEIOSIS
Seed 2
Male cone produces spores by meiosis; spores develop into pollen grains 7
Seed falls to ground and germinates, and embryo grows into tree.
Sporophyte
Figure 17.8

26. 17.9 The flower is the centerpiece of angiosperm reproduction
Most plants are angiosperms
The hallmarks of these plants are flowers
Pollen grains
Anther
Stigma
CARPEL
Ovary
STAMEN
PETAL
Ovule
SEPAL
Figure 17.9A, B

27. The angiosperm life cycle is similar to that of conifers
The angiosperm plant is a sporophyte with gametophytes in its flowers
The angiosperm life cycle is similar to that of conifers
But it is much more rapid
In addition, angiosperm seeds are protected and dispersed in fruits, which develop from ovaries

28. 2
Haploid spore in each ovule develops into female gametophyte, which produces egg.
Egg (n)
Stigma 3
Pollination and growth of pollen tube
Pollen grain
Ovule
Pollen tube 1
Haploid spores in anthers develop into pollen grains: male gametophytes.
Sperm
Pollen (n)
HAPLOID
Meiosis
Fertilization
DIPLOID 4
Zygote (2n)
Seed coat
Food supply
Seeds 7
Ovary
Seed germinates, and embryo grows into plant.
Ovule
Embryo (2n) 5
Seed
Sporophyte 6
Fruit
Figure 17.10

29. CHAPTER 31 Plant Structure, Reproduction, and Development
Modules 31.1 – 31.4

30. PLANT STRUCTURE AND FUNCTION
31.2 The two main groups of angiosperms are the monocots and the dicots
Angiosperms, or flowering plants, are the most familiar and diverse plants
There are two main types of angiosperms
Monocots include orchids, bamboos, palms, lilies, grains, and other grasses
Dicots include shrubs, ornamental plants, most trees, and many food crops

31. Monocots and dicots differ in seed leaf number and in the structure of roots, stems, leaves, and flowers
SEED LEAVES
LEAF VEINS
STEMS
FLOWERS
ROOTS
MONOCOTS
One cotyledon
Main veins
usually parallel
Vascular bundles in complex arrangement
Floral parts usually in multiples of three
Fibrous root system
DICOTS
Two cotyledons
Main veins
usually branched
Vascular bundles arranged in ring
Floral parts usually in multiples of four or five
Taproot usually present
Figure 31.2

32. 31.3 The plant body consists of roots and shoots
Root system
Provides anchorage
Absorbs and transports minerals and water
Stores food
Root hairs increase the surface area for absorption

33. Shoot system Consists of stems, leaves, and flowers in angiosperms
Stems are located above the ground and support the leaves and flowers
Leaves are the main sites of photosynthesis in most plants

34. Terminal bud
Blade
Leaf
Flower
Petiole
Axillary bud
Stem
SHOOT SYSTEM
Node
Internode
Taproot
Root hairs
ROOT SYSTEM
Figure 31.3

35. The terminal bud is located at the tip of a stem
It is the growth point of the stem
Axillary buds can give rise to branches
In apical dominance, the terminal bud produces hormones that inhibit the growth of axillary buds
This results in a taller plant that has greater exposure to light

36. 31.4 Many plants have modified roots and shoots
Roots and stems are adapted for a variety of functions
Storing food
Asexual reproduction
Protection
Plant breeders have improved the yields of root crops by selecting varieties, such as the sugar beet plant, with very large taproots
Figure 31.4A

37. Modified stems include
STRAWBERRY PLANT
runners, for asexual reproduction
rhizomes, for plant growth and food storage
tubers, for food storage in the form of starch
Runner
POTATO PLANT
Rhizome
IRIS PLANT
Rhizome
Tuber
Taproot
Root
Figure 31.4B

38. Modified leaves include tendrils and spines
Tendrils help plants to climb
Spines may protect the plant from plant-eating animals
Figure 31.4C

39. 31.6 Three tissue systems make up the plant body
Roots, stems, and leaves are made of three tissue systems
The epidermis
The vascular tissue system
The ground tissue system
Leaf
Stem
Root
Epidermis
Ground tissue system
Vascular tissue system
Figure 31.6A

40. The epidermis covers and protects the plant
The cuticle is a waxy coating secreted by epidermal cells that helps the plant retain water
The vascular tissue contains xylem and phloem
It provides support and transports water and nutrients

41. The ground tissue system functions mainly in storage and photosynthesis
It consists of parenchyma cells and supportive collenchyma and sclerenchyma cells

42. The ground tissue system of the root forms the cortex
The cortex consists mostly of parenchyma tissue
The selective barrier forming the innermost layer of the cortex is the endodermis

43. VASCULAR TISSUE SYSTEM
Xylem
Phloem
Epidermis
GROUND TISSUE SYSTEM
Cortex
Endodermis
Figure 31.6B

44. These microscopic cross sections of a dicot and a monocot indicate several differences in their tissue systems
Figure 31.6C

45. The three tissue systems in dicot leaves
The epidermis consist of pores called stomata (singular, stoma) flanked by regulatory guard cells
Figure 31.6D

46. The ground tissue system of a leaf is called mesophyll and is the site of photosynthesis
Figure 31.6D

47. The vascular tissue consists of a network of veins composed of xylem and phloem
Figure 31.6D

48. 31.7 Primary growth lengthens roots and shoots
PLANT GROWTH
31.7 Primary growth lengthens roots and shoots
Most plants exhibit indeterminate growth
They continue to grow as long as they live
In contrast, animals are characterized by determinate growth
They cease growing after reaching a certain size

49. Annuals complete their life cycle in a single year or growing season
Examples: wheat, corn, rice, and most wildflowers
Biennials complete their life cycle in two years, with flowering occurring in the second year
Examples: beets and carrots
Perennials live and reproduce for many years
Examples: trees, shrubs, and some grasses

50. Growth in all plants originates in tissues called meristems
Meristems are areas of unspecialized, dividing cells
Apical meristems are located at the tips of roots and in the terminal buds and axillary buds of shoots
They initiate primary growth, lengthwise growth by the production of new cells
Roots and stems lengthen further as cells elongate and differentiate

51. Terminal bud
Axillary buds
Arrows = direction of growth
Root tips
Figure 31.7A

52. Vascular cylinder
Cortex
Epidermis
DIFFERENTIATION
Root hair
ELONGATION
Cellulose fibers
CELL DIVISION
Apical meristem region
Root cap
Figure 31.7B

53. Leaves
Apical meristem
Axillary bud meristems 1 2
Figure 31.7C

54. 31.8 Secondary growth increases the girth of woody plants
An increase in a plant's girth results from secondary growth
Secondary growth involves cell division in two cylindrical meristems
Vascular cambium
Cork cambium

55. Cork cambium produces protective cork cells located in the bark
Vascular cambium thickens a stem by adding layers of secondary xylem, or wood, next to its inner surface
It also produces the secondary phloem, which is a tissue of the bark
Cork cambium produces protective cork cells located in the bark

56. Figure 31.8A

57. Everything external to the vascular cambium is considered bark
Secondary phloem
Cork cambium
Protective cork cells
Heartwood in the center of the trunk consists of older, clogged layers of secondary xylem
Sapwood consists of younger, secondary xylem that still conducts water

58. A woody log is the result of several years of secondary growth
Sapwood
Rings
Wood rays
Heartwood
Sapwood
Vascular cambium
Secondary phloem
Bark
Cork cambium
Cork
Heartwood
Figure 31.8B

59. 31.9 Overview: The sexual life cycle of a flowering plant
PLANT REPRODUCTION
31.9 Overview: The sexual life cycle of a flowering plant
The angiosperm flower is a reproductive shoot consisting of
sepals
petals
stamen
carpels
Anther
Carpel
Stigma
Ovary
Stamen
Ovule
Sepal
Petal
Figure 31.9A

60. Sepals are usually green and resemble leaves in appearance
Sepals enclose and protect the flower bud before the flower opens
Petals are often bright and colorful
They attract insects (pollinators)

61. Stamens are the male reproductive organs of plants
Pollen grains develop in anthers, at the tips of stamens
Carpels are the female reproductive organs of plants
The ovary at the base of the carpel houses the ovule

62. The life cycle of an angiosperm involves several stages
Ovary, containing ovule
Embryo
Fruit, containing seed
Seed
Mature plant with flowers, where fertilization occurs
Seedling
Germinating seed
Figure 31.9B

63. 31.10 The development of pollen and ovules culminates in fertilization
The plant life cycle alternates between diploid (2n) and haploid (n) generations
Double fertilization is unique to plants

64. Figure 31.10

65. 31.11 The ovule develops into a seed
After fertilization, the ovule becomes a seed
The fertilized egg within the seed divides to become an embryo
The other fertilized cell develops into the endosperm, which stores food for the embryo
A resistant seed coat protects the embryo and endosperm

66. Triploid cell
OVULE
Zygote
Two cells
Cotyledons
Endosperm
Seed coat
Shoot
Embryo
Root
SEED
Figure 31.11A

67. Seed dormancy is an important evolutionary adaptation in which growth and development are suspended temporarily
It allows time for a plant to disperse its seeds
It increases the chance that a new generation of plants will begin growing only when environmental conditions favor survival

68. Comparison between dicot and monocot seeds
Embryonic shoot
Seed coat
Embryonic leaves
Embryonic root
Cotyledons
COMMON BEAN (DICOT)
Fruit tissue
Cotyledon
Seed coat
Endosperm
Embryonic shoot
Embryonic leaf
Embryonic root
Sheath
Figure 31.11B
CORN (MONOCOT)

69. 31.12 The ovary develops into a fruit
The ovary develops into a fruit which helps protect and disperse the seeds
Figure 31.12A

70. There is a correspondence between flower and fruit in a pea plant
The wall of the ovary becomes the pod
The ovules develop into the seeds
Upper part of carpel
Ovule
Seed
Pod (opened)
Ovary wall
Sepal
Figure 31.12B

71. The sepals of the flower stay attached to the base of the green pod
The small, threadlike structure at the end of the pod is what remains of the upper part of the flower's carpel
The sepals of the flower stay attached to the base of the green pod
Upper part of carpel
Ovule
Seed
Pod (opened)
Ovary wall
Sepal
Figure 31.12B

72. Simple fruits develop from a flower with a single carpel and ovary
Apples, pea pods, cherries
Aggregate fruits develop from a flower with many carpels
Raspberries
Multiple fruits develop from a group of flowers clustered tightly together
Pineapples
Figure 31.12C

73. CHAPTER 33 Control Systems in Plants
Modules 33.1 – 33.5

74. Hormones coordinate the activities of plant cells and tissues
PLANT HORMONES
33.1 Experiments on how plants turn toward light led to the discovery of a plant hormone
Hormones coordinate the activities of plant cells and tissues
The study of plant hormones began with observations of plants bending toward light
This phenomenon is called phototropism
Figure 33.1A

75. Phototropism results from faster cell growth on the shaded side of the shoot than on the illuminated side
Shaded side of shoot
Light
Illuminated side of shoot
Figure 33.1B

76. Experiments carried out by Darwin and others showed that the tip of a grass seedling detects light and transmits a signal down to the growing region of the shoot
Light
Tip covered by trans- parent cap
Base covered by opaque shield
Tip separated by gelatin block
Control
Tip removed
Tip covered by opaque cap
Tip separated by mica
Figure 33.1C
DARWIN AND DARWIN (1880)
BOYSEN-JENSEN (1913)

77. It was discovered in the 1920s that a hormone was responsible for the signaling Darwin observed
This hormone was dubbed auxin
Auxin plays an important role in phototropism

78. Shoot tip placed on agar block
Shoot tip placed on agar block. Chemical (later called auxin) diffuses from shoot tip into agar.
Agar
Block with chemical stimulates growth.
Offset blocks with chemical stimulate curved growth.
Other controls: Blocks with no chemical have no effect.
Control
NO LIGHT
Figure 33.1D

79. Hormones regulate plant growth and development by affecting
33.2 Five major types of hormones regulate plant growth and development
Hormones regulate plant growth and development by affecting
cell division
cell elongation
cell differentiation
Only small amounts of hormones are necessary to trigger the signal-transduction pathways that regulate plant growth and development

80. Table 33.2