1. 2 Systems 3 Tissues 2 Meristems Photosynthesis Growth Reproduction
Plant Biology

2. Plant Body Systems Two types of systems: Root System
Shoot System: stem, leaf, flower
Plant organs:
root, stem, leaf, flower
referred to as plant parts

3. Root System Function Anchorage Absorption Storage
Keeps plant in the soil
Prevents soil erosion
Holds stem in place
Absorption
water
dissolved minerals
Storage
Starch
Other nutrients

4. Types of Roots

5. Taproot Large long primary root Penetrate deep into the ground
Small thin roots grow laterally off main root
Strong anchoring system
Examples: evergreen trees

6. Taproot Specialized to store water, food, nutrients
Better chance at drought survival
Examples: carrot, beet, turnip, radish

7. Fibrous Root Many small roots that branch Increases surface area
Better absorption of water and minerals
Less structural support
Examples: peas, beans, lettuce

8. Root Hairs Small fibrous objects that branch off roots
Absorbs water and minerals

9. Root Zones
Zone of maturation: cells differentiate into different types of cells
Zone of elongation: allows the root to get deeper within the soil
Meristematic region: rapid mitosis of undifferentiated meristematic cells
Root cap: protects the meristematic region

10. Shoot System
Stem
Leaf
Flower

11. Stem Raises and supports branches, leaves and flowers
Transport of water and nutrients
In trees the main stem is the tree trunk

12. Stem
Young green stems can perform photosynthesis because they have chloroplast in their epidermal cells

13. Stem Some are specialized for food storage
Examples: sugar cane, potatoes
Stem

14. Leaf Main function: Photosynthesis Parts of the Leaf: Cuticle
Epidermis
Guard Cells & Stoma
Palisade cells
Spongy Layer
Vascular Tissue

15. Epidermis Outer layer of cells Leaf epidermis produces cuticle

16. Cuticle Waxy substance that coats the exterior Water proofing
Protect interior tissues
Blocks passage of gases

17. Guard Cells & Stoma Stoma (Greek for “mouth”)
Pore-like openings in the plant’s epidermis
Opening size controlled by two guard cells
permits gas exchange between the leaf’s interior and external environment.
larger opening, faster gas exchange

18. Guard Cells & Stoma

19. Spongy Layer
Where water is stored
Where the vascular tissues reside

20. Palisade Cells Contains many chloroplast for photosynthesis
Cells stand tall and upright
Top end exposed to light
Bottom end exposed to the gases in the spongy layer

21. Chloroplast Structure
Thylakoids are flat disc-like structures where chlorophyll is embedded
Grana are thylakoids arranged in a stack
Chlorophyll is a pigment that captures light energy

22. CO2 + H2O + energy  O2 + glucose
Chloroplast Function
Site for starch (a type of sugar) storage
Site for photosynthesis
Reaction involves trapping light energy to create food in the form of sugars
Starting substances are carbon dioxide and water
CO2 + H2O + energy  O2 + glucose

23. Leaf Cross Section
Scanning electron microscope image of a leaf from a Black Walnut tree. (Dartmouth Electron Microscope Facility/Dartmouth College)

24. Modified Leaf: Cactus

25. Poinsettia Leaves

26. Flower
Specialized structures developed for sexual reproduction known as pollination
Can contain both male and female reproductive structures in the same flower

27. Flower Parts Male reproductive organ: stamen
Female reproductive organ: pistil

28. Flower Parts Male gametes: pollen grains found on anther
Female gametes: ovule housed in ovary

29. Pollination Act of sexual reproduction in plants
Pollen reach stigma, travel down the style into the ovary to fertilize the ovule

30. Methods of Pollination: Wind
Pollen grains blown by wind
Plants are often small and drab but produce a large amount of pollen
Example: grass

31. Methods of Pollination: Animals
Pollinators:
Animals: birds, bats, and on fur of land animals
Insects: bees
Plants attract pollinators with:
Large, colourful fragrant flowers
nectar

32. Methods of Pollination: Animals
Example: Dandelion plant attracting bees

33. After Pollination Zygote (fertilized egg) becomes the seed
Ovary becomes the fruit

34. After Pollination Zygote (fertilized egg) becomes the seed
Ovary becomes the fruit

35. After Pollination

36. Plant Tissue
Dermal Tissue
Vascular Tissue
Ground Tissue

37. Dermal Tissue Outermost layer of a plant
Epidermis: thin layer of cells that covers the surface of leaf, stem and root
Periderm tissue: bark on stem and large roots of woody plants (replaces the epidermis)

38. Dermal Tissue Some dermal tissues have unique functions
Root cells: root hairs (long extensions)
Leaf cells: produce cuticle

39. Vascular Tissue Plant circulatory system
Vessels that connect roots to leaves
Transports water, dissolved minerals, and sugars throughout plant, providing cells with materials to carry out life functions
Two types:
Xylem
Phloem

40. Vascular Tissue: Xylem
made up of long hollow tubes formed by non-living cell walls (left over from plant cells that have died)
transports water and dissolved minerals upwards from roots

41. Vascular Tissue: Phloem
Made up of elongated cells that are living
Transports:
solutions of sugars (food)
Dissolved nutrients
Hormones
Bi-directional movement of materials
downward to roots
upward to leaves

42. Vascular Bundle

43. Plant Sugars Starch is NOT soluble in water
Starch can be broken down into sucrose
Sucrose IS soluble in water
Sucrose is transported through the phloem to the plant parts that require it
Sucrose can be broken down into glucose
Glucose is used in cellular respiration to make cellular energy
Starch  sucrose  glucose

44. Spring Trees need energy to grow leaves
Energy comes from cellular respiration of glucose:
Glucose + oxygen  carbon dioxide + water + energy
Glucose can be obtained by:
Photosynthesis - but spring trees don’t have any leaves to do photosynthesis
Converting it from starch

45. Spring Starch Sucrose Glucose Stored in the roots
Insoluble in water so it cannot be transported through phloem
Convert to sucrose
Sucrose
Soluble in water
Transport from root to tree bud through phloem
Convert to glucose in tree bud
Glucose
Use in cellular respiration
Converted to cellular energy needed to grow leaves

46. Tree Sap Starch Sucrose Glucose Roots Stem Leaves Storage Transport
Photosynthesis

47. Plant Sugars Sugar Solubility in water Location Function Starch No
Root
Storage
Sucrose
Yes
Stem
Transport
Glucose
Leaf
Cellular respiration

48. Summer
Once leaves have grown, they can perform photosynthesis to produce their own glucose
Glucose is converted to sucrose and transported through the phloem to the roots
Sucrose is converted to starch in the roots for storage

49. Sugar Movement through Phloem
Glucose
(leaves)
Sucrose
(stem)
Starch
(roots)
Winter storage
Spring
Summer and Fall
Spring
Summer and Fall

50. Cells in the Root
Cells in the root have no chloroplasts and are not exposed to sunlight so they can not undergo photosynthesis to make their own food
Root cells must perform cellular respiration to obtain cellular energy
Glucose + oxygen  carbon dioxide + water + energy
Glucose comes from the starch stored in the root
Oxygen is absorbed through the soil

51. Ground Tissue Filler tissue in between the dermal and vascular tissue
Variety of processes depending on where it is in the plant
In leaf: palisade and spongy mesophyll cells