1. Anatomy, Morphology, & Growth of Angiosperms – Ch. 5-8
BOT 101
Anatomy, Morphology, & Growth of Angiosperms – Ch. 5-8

2. Two plant groups: monocots & dicots
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Two plant groups: monocots & dicots

3. Structure Reflects Function
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Structure Reflects Function

4. Structure of a plant determined by:
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Structure of a plant determined by:
Genetics
Environment – two time scales:
Long-term:
Short-term: plasticity = wide range of phenotypes for each genotype. Allows plants to adjust to changing environment (ex. Shorter plant in dry year so that it can still reproduce)

5. Muscle cell Cells Tissues Muscle tissue Organs Heart
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Muscle cell
Cells
Tissues
Muscle tissue
Organs
Heart
Circulatory system
Systems

6. Three organs: Roots, stems, leaves
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Three organs: Roots, stems, leaves
Roots–
Store food (carbos from photosynthesis) to be used for flowering & fruiting
Covered with root hairs – increased surface area for absorption

7. BOT 101
Fig 35.2

8. Modified Roots – Fig 35.4 Prop roots Aerial strangler roots
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Prop roots
Aerial strangler roots
Sweet Potato – storage root
Modified Roots – Fig 35.4
Buttress roots
Pneumatophores

9. 2. Stems/shoots Support, transport Some photosynthesis
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2. Stems/shoots
Support, transport
Some photosynthesis
Two types of shoots
Vegetative –
Reproductive –
Two parts of stem:
Node –
Internode – stem segments between nodes

10. BOT 101
Two types of buds
Terminal bud – contains a shoot apical meristem; shoot growth is concentrated here
Axillary buds –
Apical dominance = the presence of an apical bud inhibits the growth of axillary buds.
-remove or depress apical bud, axillary buds begin to grow.

11. Modified Shoots (stems):
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Modified Shoots (stems):
Stolons –
Rhizomes –
Bulbs – swollen underground shoots
Tubers – swollen rhizomes
Asexual, vegetative propagation
Stores food for later growth

12. BOT 101
Fig 35.5

13. 3. Leaves – main photosynthesis organs
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3. Leaves – main photosynthesis organs

14. BOT 101
Modified leaves
Compound, doubly compound – why??

15. BOT 101
Tendrils
Fig 35.7 – Modified leaves
Spines
Succulents

16. Compound leaf = divided into distinct units called leaflets
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Leaf types:
Simple leaf =
Compound leaf = divided into distinct units called leaflets

17. Four types of leaf arrangement: Acaulescent –
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Four types of leaf arrangement:
Acaulescent –
Alternate –
Opposite – leaves borne across from each other at the same node
Whorled – 3 or more leaves arising from the same node.

18. BOT 101

19. Three main tissues: Dermal, Vascular, Ground
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Three main tissues: Dermal, Vascular, Ground
Fig 35.8

20. Dermal tissue or epidermis
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Dermal tissue or epidermis
Root hairs are specialized epidermal extensions
Secretes waxy cuticle of the leaf

21. BOT 101
2. Ground Tissue
fills the space between dermal and vascular tissue systems.
Diverse functions:
pith
In dicots:
cortex

22. BOT 101
3. Vascular Tissue
function in transport between roots & shoots, and structural support of plant
Xylem:
Phloem: Food transported to roots & non-photosynthetic parts such as the flowers

23. BOT 101
The Plant Cell
Fig 7.8

24. 5 Differentiated Plant Cell Categories
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5 Differentiated Plant Cell Categories
Parenchyma
Collenchyma
Schlerenchyma
Water-conducting cells of the xylem
Sugar-conducting cells of the phloem

25. BOT 101
1. Parenchyma
thin and flexible cell walls

26. BOT 101
2. Collenchyma
Usually grouped in strands to support young parts of plants without restraining growth
Flexible, elongate with growing shoots

27. 3. Schlerenchyma May be dead at functional maturity – ???
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3. Schlerenchyma
May be dead at functional maturity – ???
cell walls left behind as skeleton

28. BOT 101

29. 4. Water conducting cells of the xylem:
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4. Water conducting cells of the xylem:
2 types: tracheids & vessel elements

30. BOT 101
Tracheids
Water flows from cell to cell (laterally) through pits in cell wall
Support function

31. Vessel Elements End walls are perforated for free flow of water
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Vessel Elements
End walls are perforated for free flow of water
More efficient as water conductors than tracheids

32. BOT 101
Fig 35.9

33. 5. Sugar-conducting cells of the phloem
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5. Sugar-conducting cells of the phloem
Sieve-tube members:
Lack a nucleus, ribosomes, vacuole
Cells separated by perforated sieve plates – allow sugar movement

34. BOT 101
Fig 35.9

35. Growth & Development BOT 101

36. BOT 101
Development =

37. Three processes of development:
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Three processes of development:
Growth =
Cellular differentiation = generation of different cell types
Morphogenesis – creation of body form & organization.

38. BOT 101
1. Growth
Cell division no expansion

39. BOT 101
Growth
= due to water uptake in the vacuole

40. BOT 101
Fig 35.24

41. BOT 101
Cell division
Occurs in only in meristems!

42. Meristems = Two types of meristems: Apical meristem –
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Meristems =
Two types of meristems:
Apical meristem –
Lateral meristems – extend lengthwise along the axis of the stem & roots. Responsible for growth in girth in older parts of the plant (called secondary growth). Exist only in perennials

43. BOT 101
Fig 35.10

44. Primary Growth of Roots
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Primary Growth of Roots
Root cap – layer of cells that protect the RAM as it pushes through the soil

45. BOT 101
Fig 35.12

46. Arrangement of Primary Tissues in Roots
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Arrangement of Primary Tissues in Roots
Epidermis –
Stele –
Ground tissue – mostly parenchyma cells of the cortex – area between the stele & epidermis; stores food & takes up minerals.
Endodermis – single cell layer between cortex & stele. Selective barrier for uptake of soil solution contents into vascular system.

47. Eudicot/Gymnosperm root cross section
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Eudicot/Gymnosperm root cross section
Epidermis
Endodermis
Cortex
Stele
xylem
phloem
Fig 35.13

48. Primary Growth of Shoots
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Primary Growth of Shoots
Bud = cluster of leaf primordia created by meristem. No internodes
Lateral branches arise from axillary buds

49. BOT 101
Fig 35.15

50. Primary tissue arrangement of stems
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Primary tissue arrangement of stems
Ground tissue = pith & cortex

51. Eudicot/Gymnosperm stem cross section pith
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Eudicot/Gymnosperm stem cross section
pith
phloem
cortex
xylem
epidermis
Fig 35.16
Schlerenchyma cells

52. Tissue arrangement of leaves
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Tissue arrangement of leaves
3 parts:
Upper & lower epidermis – tightly interlocked cells, secrete waxy cuticle. Contains stomata flanked by guard cells
Vascular tissue –
Mesophyll – ground tissue between upper & lower epidermis

53. BOT 101
Fig 35.17

54. Secondary Growth Two lateral meristems:
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Secondary Growth
Two lateral meristems:
Vascular cambium – produces secondary xylem (= wood) & phloem
Cork cambium – replaces the epidermis with cork: tough, thick cover for stems, roots.

55. Secondary growth of stems
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Secondary growth of stems
Vascular cambium – layer of cells between primary xylem & primary phloem. Puts on successive layers of secondary phloem to outside & secondary xylem to inside =====> stem widens
Wood = accumulation of secondary xylem. Dead at maturity, contains lignin

56. BOT 101
Cork cambium
“bark” =
Cork continually sloughs off

57. BOT 101
Fig 35.18

58. BOT 101

59. BOT 101
Fig 35.20

60. Three types of life cycles:
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Three types of life cycles:
Annual –
Biennial – complete life cycle in two years (first year = vegetative, second year = reproductive). Some need a cold winter period to initiate flowering from vegetative state. Ex. carrots
Perennial – live year after year, do not die after reproduction. Examples: trees, shrubs, some grasses. Causes of death = fire, disease