1. Kingdom PLANTAE Multi-celled / eukaryotic Autotrophic / chloroplast
Cell wall - cellulose

2. Kingdom PLANTAE
Plant Evolution

3. Plants: Alternation of Generation
Gametophyte (n): Haploid, produces eggs and sperms which then unite to form sporophyte
Sporophyte (2n): Diploid which goes through meiosis to produce spores which grow into gametophytes

4. Plants: Alternation of Generation

5. Plants: Alternation of Generation - MOSSES

6. Plants: Alternation of Generation - FERNS

7. Plants: Flowers Alternation of Generation

8. Plants: Flowers Most plants are angiosperms, flowering plants
Angiosperm seeds protected and dispersed in fruits, which develop from ovaries

9. Plants: Flowering Plants
Angiosperms, or flowering plants, are most familiar and diverse plants
Two main types of angiosperms
Monocots: orchids, bamboos, palms, lilies, grains, and other grasses
Dicots: shrubs, ornamental plants, most trees, and many food crops

10. 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)

11. Plants: Monocots vs Dicots

12. Plants: Flowering Plant Reproduction
The angiosperm flower is a reproductive shoot consisting of
sepals
petals
stamen
carpels
Anther
Carpel
Stigma
Ovary
Stamen
Ovule
Sepal
Petal
Figure 31.9A

13. Plants: Stamens - male reproductive organs of plants
Pollen grains develop in anthers, at the tips of stamens
Carpels - female reproductive organs of plants
Ovary at the base of the carpel has ovule

14. Life cycle of 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

15. Figure 31.10

16. Plants: The ovule develops into a seed
After fertilization, ovule becomes seed
Fertilized egg inside seed - embryo
Other fertilized cell - endosperm, stores food for the embryo
Resistant seed coat protects the embryo and endosperm

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

18. 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

19. Plant: Asexual Reproduction
Bulbs: parts of root split and form new bulb (ex. tulip)
Tubers: modified underground stem have buds (ex. potato)
Runners: plant stem run above ground (ex. Strawberry)
Rhizomes: woody underground stem (ex. Iris)

20. Modified stems include
STRAWBERRY PLANT
runners, asexual reproduction
rhizomes, plant growth and food storage
tubers, food storage as starch
Runner
POTATO PLANT
Rhizome
IRIS PLANT
Rhizome
Tuber
Taproot
Root
Figure 31.4B

21. Asexual runners
Figure 31.14D

22. Plant: Asexual Reproduction
Vegetative propagation: cuttings or bits of tissue increase agricultural productivity
But it can also reduce genetic diversity
Cutting: cut stem form roots
Layering: bent stem touching ground form roots
Grafting: stock of one grafted on stem (scion) of another

23. Plants: Shoot and Root System
Provides anchorage
Absorbs and transports minerals and water
Stores food
Shoot system
Consists of stems, leaves, and flowers in angiosperms
Stems: located above ground and support leaves and flowers
Leaves: main sites of photosynthesis in most plants

24. Plant: Cell Structure

25. Plants: 3 Tissue Systems
Instead of organs, plants have roots, stems, and leaves are made of three tissue systems
The epidermis
The vascular tissue system
The ground tissue system

27. PLANTS: Epidermis and Vascular Tissue
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
Xy: high (water) Phlo: lo (nutrients)
Rise of water: transpiration pull, capillary action, root pressure

28. Phloem transports food molecules made by photosynthesis
Figure 32.5B

29. Figure 32.3

30. Plants: Vascular & Ground Tissue
Vascular tissue:
Xylem: inside, bring water up; usually dead cells act as tube
Phloem: outside bundle, brings nutrients down
Pith: storage and structure
Cambium: growth tissue – divide into xylem and phloem (2nd growth)
The ground tissue system functions mainly in storage and photosynthesis

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

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

33. Three tissue systems in dicot leaves
Epidermis: stomata (singular, stoma) surrounded by guard cells – regulate opening/closing of stomata
Figure 31.6D

34. Ground tissue system of a leaf – mesophyll, site of photosynthesis
Figure 31.6D

35. Vascular tissue: xylem and phloem
Figure 31.6D

36. Plants: Guard cells control transpiration
Opening and closing of stomata - adaptation to help plants regulate water content / adjust to changing environmental conditions
Guard cells
H2O
H2O
H2O
H2O
H2O
H2O K+
H2O
Vacuole
H2O
H2O
H2O
Stoma opening
Stoma closing
Figure 32.4

37. Plant Growth: Primary vs Secondary
Most plants continue to grow as long as they live (as opposed to animals that stop growing)
Two types of growth:
- primary growth (length)
- secondary growth (width)

38. Plants: Primary Growth
Growth from tissue meristems
Meristems: unspecialized, dividing cells (like our stem cells)
Apical meristems: tips of roots and stems and terminal buds ; length growth
Primary growth (length growth) - new cell productions

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

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

41. Plants: Secondary growth
Secondary growth: Increase in a plant's width
Lateral meristem (also called cambium):
Vascular cambium (located between xylem and phloem)
Cork cambium (not in grasses or herbs, but found in woody dicots, ex. oaks)

42. Cork cambium produces protective cork cells located in bark
Vascular cambium thickens stem by adding layers of secondary xylem, or wood, next to its inner surface
Also produces secondary phloem- tissue of bark
Cork cambium produces protective cork cells located in bark

43. Figure 31.8A

44. Plants: Secondary Growth
Everything outside vascular cambium – bark
Secondary phloem
Cork cambium
Protective cork cells

45. Woody log result of several years of secondary growth (inside “dead”; outside “growing”)
Sapwood
Rings
Wood rays
Heartwood
Sapwood
Vascular cambium
Secondary phloem
Bark
Cork cambium
Cork
Heartwood
Figure 31.8B

46. Plant: Behavior = Tropism
Phototropism
Gravitropism
Geotropism
thigmotropism
Figure 33.1A

47. Phototropism is the bending toward light
It may result from auxin moving from the illuminated side to the shaded side of a stem
Figure 33.1A

48. Gravitropism is a response to gravity
Figure 33.9A

49. Thigmotropism - response to touch
Responsible for coiling of tendrils and vines around objects
Enables plants to use other objects for support while growing toward sunlight
Figure 33.9B

50. Phototropism Shaded side of shoot Light Illuminated side of shoot
Figure 33.1B

51. Hormone controls phototropism
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)

52. 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

53. Plants: Hormones
Hormones affect:
cell elongation
cell differentiation

54. Table 33.2

55. Auxin: stimulates cell division – phototropism and geotropism
Positive and negative geotropism (b/c unequal distribution of hormone, unequal growth & root grows faster)

56. Plants: Hormones Cytokinins: promote cell division
Produced in actively growing roots, embryos, and fruits
Opposite auxin, so plant coordinates growth of root and shoot systems

57. Cytokinins – develop side growth Ex grow branch
Auxin – stimulate length growth
w/o auxin, plant becomes thicker b/c cytokinins
Terminal bud
No terminal bud
Figure 33.4

58. Plants: Hormones
Gibberellins: stimulate cell elongation and cell division in stems and leaves
Gibberellins: can stimulate seed growth
Figure 33.5A

59. Gibberellins with auxin - influence fruit development
Grapes at right treated with gibberellin, left not
Figure 33.5B

60. Plants: Hormones Abscisic acid (ABA) inhibits germination of seeds
Ratio of ABA & gibberellins determines whether seed remain dormant or germinate
Also “stress hormone” – close stomata when too dry

61. Seeds of many plants remain dormant until ABA inactivated or washed away
Ex. flowers grow from seeds after rainstorm in Mojave Desert
Figure 33.6

62. Plants: Hormones Ethylene: triggers fruit ripening
Given off as cells age
Figure 33.7A

63. Fruit growers use ethylene to control ripening
Apple farmers slow down ripening action of natural ethylene
Tomato farmers pick unripe fruit and then pipe ethylene into storage bins to promote ripening

64. Plants: Circardian Rhythms
Circadian rhythms: internal biological clock controls daily cycles
Even in the absence of environmental cues, they persist with periods of about 24 hours
But such cues are needed to keep them synchronized with day and night
Figure 33.10