1. Plants

2. What is a plant?
Eukaryotic Multicellular Autotrophic

3. Why are plants important?
Food
Oxygen
Materials (building, paper, clothes)
Aesthetics
Shelter
Medicine

4. Plant Tissues
Vascular Tissue: interconnected cells that make tubes for transport Xylem: move water from the roots to the leaves Phloem: move sugar from roots to leaf buds (Spring) or leaves to roots (Fall)

5. Figure. 35.9 100 m SUGAR-CONDUCTING CELLS OF THE PHLOEM
WATER-CONDUCTING CELLS OF THE XYLEM
Vessel
Tracheids
100 m
Tracheids and vessels
element
Vessel elements with
partially perforated
end walls
Pits
SUGAR-CONDUCTING CELLS OF THE PHLOEM
Companion cell
Sieve-tube
member
Sieve-tube members:
longitudinal view
Sieve
plate
Nucleus
Cytoplasm
Companion
cell
30 m
15 m

6. Storage Tissue: stores food as starch
Storage Tissue: stores food as starch Collenchyma – crunchy cells – carrots and potatoes

7. Support Tissue: gives strength to tissues. Sclerenchyma – stick like
Support Tissue: gives strength to tissues Sclerenchyma – stick like Xylem

8. Protective Tissue: keep water in and invaders out. Cork on stems
Protective Tissue: keep water in and invaders out Cork on stems Epidermis on leaves – makes a waxy layer called the cuticle

9. Prickle
Rose “thorns” are prickles  “A rose between two prickles.”

10. Photosynthetic Tissue: Parenchyma/Mesophyll: inside of leaves

11. Cortical parenchyma cells
Figure 35.9
Parenchyma cells
60 m
PARENCHYMA CELLS
80 m
Cortical parenchyma cells
COLLENCHYMA CELLS
Collenchyma cells
SCLERENCHYMA CELLS
Cell wall
Sclereid cells in pear
25 m
Fiber cells
5 m

12. Plant Organs
Roots: - hold plant in the soil - absorb water and nutrients - store food - reproduction

13. (a) Prop roots
(b) Storage roots
(c) “Strangling” aerial roots
(d) Buttress roots
(e) Pneumatophores

14. Stems: - support leaves and reproductive structures - can be specialized to store food or water or reproduction (potato, strawberry runners, bamboo shoots) - modified for defense = thorn

15. Thorn

16. Leaves: - photosynthesis - can store water (succulent) - modified for defense = spine (cactus) - specialize for reproduction = flowers

17. Spine

18. External Structure of Leaf

19. Leaves: External Structure
Blade
Petiole
Stipule
Axillary Bud
Veins

20. Internal Structure of Leaf

21. Leaf Mesophyll

22. Leaf Stomata

23. Leaf Modifications
(a) Tendrils. The tendrils by which this pea plant clings to a support are modified leaves. After it has “lassoed” a support, a tendril forms a coil that brings the plant closer to the support. Tendrils are typically modified leaves, but some tendrils are modified stems, as in grapevines.
(b) Spines. The spines of cacti, such as this prickly pear, are actually leaves, and photosynthesis is carried out mainly by the fleshy green stems.
(c) Storage leaves. Most succulents, such as this ice plant, have leaves modified for storing water.
(d) Bracts. Red parts of the poinsettia are often mistaken for petals but are actually modified leaves called bracts that surround a group of flowers. Such brightly colored leaves attract pollinators.
(e) Reproductive leaves. The leaves of some succulents, such as Kalanchoe daigremontiana, produce adventitious plantlets, which fall off the leaf and take root in the soil.

25. Important Structures
Stoma: opening for gas exchange Guard Cells: regulate size of stoma Mesophyll: photosynthesis Cuticle: protective waxy layer Vascular Bundle: xylem and phloem – vein of leaf

26. Types of Plants
Non-vascular plants: No xylem or phloem – can only move water and sugar by osmosis and diffusion – keeps them small Ex: Bryophytes: Mosses and the their relatives (Liverworts, Hornworts) - reproduce using spores – produced in specialized structures called sporangia - require water for reproduction – sperm must swim to the egg

28. Vascular Plants: Have xylem and phloem
Types of Vascular Plants: Seedless vascular plants: Reproduce using spores EX: Ferns – produce spores which grow in sprorangia on the underside of the leaf, which is called a Frond

31. - spores land on ground and grow into a separate plant which produces the eggs and the sperm - water hits this and allows the sperm to swim to the egg and the zygote grows into a new fern
Other Types: Horsetails, Ground Pine

33. Seed Plants: Produce specialized structures (Cones or Flowers) that make egg cells in an ovary and sperm cells which are housed inside of pollen grains pollen is transferred to the cone or flower by a pollinator (insects, birds, bats) to make a new plant and a food source which is protected inside of a seed and the cone or the developing fruit

34. Types of Seed Plants
Gymnosperms: “naked” seeds – seeds only have a seed coat and are not protected by a fruit Ex: Conifers: cone bearing trees
- produce two types of cones: Male cones (make pollen) – very small Female cones (make eggs) – egg is housed in the scales of the cone

35. pollen is blown by the wind from the male cone to the female cone and fertilizes the egg – cone scales close and protect the developing seed – sperm and egg fuse to make the embryo and other unfertilized eggs divide to make a food source in the seed – after several years the scale opens and releases the seeds – some conifers require the heat and smoke from fire to cause the cones to open and release the seeds

37. Angiosperms: “combined” seeds – seeds that develop from flowers and have a protective coating around the seeds that is the mature ovary of the plant  fruit - Flowering Plants

38. Typical Flower Structure and Reproductive Cycle

39. Reproduction: Ovary produces egg cells, anthers produce pollen (houses the sperm and a specialized cell called the tube cell) - pollen is transferred to the stigma and germinates releasing the tube cell and the sperm cell
Tube cell makes a path for the sperm cells to the opening of the ovary

40. One sperm fertilizes one egg to make the new plant embryo and the other sperm fertilizes two other egg cells to make the food source = double fertilization
The food source develops into the seed part that we eat and the embryo develops into the young plant
At the same time the wall of the ovary begins to grow and expand forming the fruit to attract animals or help spread the seeds

41. Types of Fruits: - Dry fruits: sunflower seeds, Maple tree helicopters, burrs, dandelion tufts - Fleshy fruits: Apples, bananas, tomatoes, peppers, cucumbers, avocado, peas, green beans

42. Types Of Angiosperms: Monocots and Eudicots – “cot” refers to the cotyledon or the “seed leaf” in the seed – the first leaf/leaves that emerge from the growing embryo - embryonic leaves

44. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
Leaf Veins
Roots
Vascular Bundles in Roots
Vascular Bundles in the Stems
Secondary Growth

46. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
In multiples of 3
In multiples of 4 and 5
Leaf Veins
Roots
Vascular Bundles in Roots
Vascular Bundles in the Stems
Secondary Growth

47. Eudicot Flower: multiples of 4 & 5
From:
From: eedsite.co.uk/brassica ceae.gif

48. Monocot Flower: Multiples of 3
From:

49. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
In multiples of 3
In multiples of 4 and 5
Leaf Veins
Parallel
Net pattern
Roots
Fibrous
Tap root
Vascular Bundles in Roots
Vascular Bundles in the Stems
Secondary Growth

50. Eudicot & Monocot Leaf Veination
Eudicot – net venation
Monocot – parallel venation

51. Eudicot & Monocot Roots - External
Eudicot – tap root
Monocot – fibrous roots

52. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
In multiples of 3
In multiples of 4 and 5
Leaf Veins
Parallel
Net pattern
Roots
Fibrous
Tap root
Vascular Bundles in Roots
Xylem in a Circle
Xylem in an “X”
Vascular Bundles in the Stems
Secondary Growth

53. Monocot Root Cross Section
From:

54. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
In multiples of 3
In multiples of 4 and 5
Leaf Veins
Parallel
Net pattern
Roots
Fibrous
Tap root
Vascular Bundles in Roots
Xylem in a Circle
Xylem in an “X”
Vascular Bundles in the Stems
Scattered throughout – look like little faces
Along the outer edge
Secondary Growth

55. Monocot Stem Vascular Bundles
Xylem
Phleom

56. Monocot Stem Vascular Bundle
From:

58. Eudicot Stem Cross Section
From:

59. Eudicot Stem Vascular Bundle
Sclerenchyma
Phloem
Xylem
Vascular Cambium

60. Characteristic
Monocots
Eudicots
Seed Structure
One “seed leaf” – made of one piece
Two “seed leaves” – made of two pieces
Flowers Parts
In multiples of 3
In multiples of 4 and 5
Leaf Veins
Parallel
Net pattern
Roots
Fibrous
Tap root
Vascular Bundles in Roots
Xylem in a Circle
Xylem in an “X”
Vascular Bundles in the Stems
Scattered throughout – look like little faces
Along the outer edge
Secondary Growth
Absent
Present – forms layers of new growth each year – makes rings of xylem tissue  Annual Rings

61. Life Cycles: Annuals: live for one year and then die Biannual: grow for one year but do not flower – flower the second year and then die Perennials: live for more than two years and up to thousands