1. Transport in plants (13.4) and Plant Reproduction
5.3

2. Plant Tissues
Groups of specialized cells form tissues except when dormant (ex. during extreme cold or heat)
These tissues include dermal, ground and vascular tissue.

3. Plant Tissues Located In Various Organs

4. Dermal tissue
Dermal tissue forms the outermost covering of the plant’s organs. It forms a protective barrier and controls the exchange of water and gases between the plant and its environment. An epidermal cell is one type of cell that forms dermal tissue.

5. Ground tissue Ground tissue has several functions
Some ground tissue is responsible for photosynthesis, other tissues provide support for the plant’s body

6. Vascular Tissue
Vascular tissue is responsible for transporting water, nutrients and sugars throughout the plant (ex. xylem and phloem)
It also helps to provide physical support for the plant’s body

7. Vascular tissue (Xylem & Phloem)
Xylem transports water and minerals from plant roots to other parts of the plant
Phloem transports sugars from leaves to other parts of the plant

9. Sugar and Water Movement in Plants

10. Transpiration
90% of water that enters the leaf is lost out of stomata through transpiration

11. How is water transported 100m up without muscles?
Positive pressure (pushing)
Root pressure
Negative pressure (pulling)
Transpirational pull

12. Water Movement
Water is moved up from the roots of the plants, up the stem and out the leaves by the Transpiration-Pull Theory (Cohesion-Tension pull theory).

13. Water Movement
The theory is based on the three key properties of water:
Cohesion: the ability of water molecules to stick together
Adhesion: the ability of water molecules to stick to the sides of hollow tubes.
The high surface tension of water.

14. Water Movement
Water molecules are absorbed into the roots through the process of osmosis.
Here water is forced through the endodermis into the xylem, but only if the xylem has room for it.

15. Water Movement
At the leaves, water is being used in photosynthesis or it is evaporated out of the leaf through the stomata (a process known as transpiration)
Due to the cohesion of water molecules, as one is pulled out of the stomata or used in the leaf, another takes its place.

16. Water Movement
Due to adhesion, the water is able to stick to the sides of the xylem tubes and not slide back down towards the root.

17. Water Movement
This occurs throughout the entire length of xylem in the plant!
Due to these properties, water can be pulled against the force of gravity upwards of hundreds of feet!

18. Water Movement
As water is being pulled up through the stem, more water is forced through the endodermis of the root to replace water lost at the leaves, so there is a continual flow of water through the plant.

19. Sugar Movement

20. Sugar Movement This process is known as the Pressure-Flow Theory
It was suggested by Ernst Munch, a German plant physiologist, in 1926.

21. Sugar Movement
Glucose is created at the leaf (The Source) during photosynthesis. Glucose is changed into the disaccharide sucrose in order to be transported in the plant.

22. Sugar Movement
This sucrose is actively transported (uses energy) into the phloem cells in the leaf.
There is a high concentration of sugar (sucrose) in the phloem at the source.

23. Sugar Movement
Because there is so much sugar in the phloem, some water moves in from the xylem to try and balance out the concentration.
This creates a high amount of pressure in the phloem near the source.

24. Sugar Movement
Meanwhile sugar is being actively transported into the root or any other storage area in the plant (The Sink).
Sinks have lots of sugar (usually joined together to form starch).
The phloem cells around a sink have low amounts of sugar and therefore water will leave them and cause them to have a low amount of pressure.

25. Sugar Movement

26. Sugar Movement
Due to the difference in pressure in the phloem cells at the Source and the Sink, sugar will be forced down the phloem along this pressure gradient.

28. Learning Check
Pg 563, Q 25-30
Pg 566, Q 1,2,3

29. Plant Reproduction

30. Angiosperms (flowering plants)
Plants that protect their seeds within the body of a fruit.
Make up ¾’s of all plants, including:
Trees, shrubs, herbs,
grasses, water plants…

31. Structure of a Flower 1. Pistil 2. Stigma 3. Style 4. Ovary 5. Stamen
6. Filament
7. Anther
8. Petal
9. Sepal
10. Receptacle
11. Stem

32. Male Reproductive Structure
The stamen consists of two parts: Anther and Filament
The anther is where meiosis occurs to produce haploid pollen
The filament is a stalk that supports the anther

33. Female Reproductive Structure
The pistil consists of the stigma, style and ovary
The sticky stigma receives the pollen from the anther
The pollen grows a tube down through the style
Meiosis occurs in the ovary to produce haploid ovules

34. Reproductive Structures
Petals: colourful
structures that attract pollinators.
Sepals: surround and protect the flower bud.

35. Learning Check
Pg 584, Q 1-6

36. Structural Differences
Complete Flowers
Sepals, petals, stamens and pistils
Incomplete Flowers
Missing one or more of the above
Perfect Flowers
Have both pistils and stamens
Imperfect Flowers
Have either pistils or stamens, but not both

37. Monoecious Dioecoious
plants have individual flowers that are imperfect but they have both male and female flowers (oaks, corn)
Dioecoious
Plants that have reproductive structures divided between two plants (willow)

38. Pollination Self-pollinating plants Cross-pollinating plants
Pollinate themselves (either same flower or elsewhere on plant
Loss of genetic variation
Cross-pollinating plants
Most angiosperms
Receive pollen from another plant
Ensures genetic diversity

39. Pollination
Wind, insects or other animals transfer pollen from the anther of one flower to the stigma of another
Flowers vary depending on pollination mechanism

40. Pollination Vectors Wind Pollination: Dull, scentless
flowers with reduced petals
Bees/Butterfly Pollination: Bright
color, nectaries, scent.
They sip nectar, get pollen on coats,
transfer pollen from flower to flower
Bird Pollination: Nectaries, bright
colors, tube-like flowers
Moth Pollination: White petals,
open at night
Fly Pollination:Rank odor, flesh
colored petals

41. Seed and Fruit Development
After fertilization, the petals and sepals fall off flower
Ovary “ripens” into a fruit
The ovule develops into a seed

42. Seed Dispersal Mechanisms- Allow plants to colonize new areas and avoid shade of parent plant
Wind Dispersal - Flight mechanisms,
like parachutes, wings, etc.
Ex. Dandelion, maples, birch
Animal Dispersal - Fleshy fruits which
animals eat, drop undigested seeds in
feces or burrs which stick to
animals’ coats

43. Gravity Dispersal - Heavy nuts fall to ground and roll
ex. acorns
Water Dispersal - Plants
near water create floating
fruits
ex. coconuts

44. Learning Check
Pg 586, Q 7-12

45. Pollen Grain Anther Sac
Pollen grains contain two haploid cells produced through meiosis.
1- The Tube cell – will grow the pollen tube.
2- The Generative cell – will go through mitosis to create two sperm cells.

46. Ovary
Each ovule within an ovary has a micropyle (an opening for the pollen tube).
The ovules’ megasporangium undergo meiosis to produce four haploid cells (3 die leaving 1 megaspore)
The megaspore undergoes mitosis 3 times to produce 8 haploid cells within the embryo sac.

48. Fertilization
After pollen lands on the stigma, a pollen tube grows down through the style to ovary
Generative cell creates the two sperm nuclei
Double fertilization occurs:
one sperm fertilizes the egg
one sperm the two polar nuclei together

49. Result of Double Fertilization
The sperm nucleus and egg nucleus join to form a 2n (diploid) embryo
The other sperm nucleus and the two polar nuclei join to form a 3n (triploid) endosperm. The endosperm is the food supply for the embryo.
First link

50. SEED GERMINATION
Seeds initially germinate as they absorb water, bursting the seed coat so the growing plant can produce energy
This starts a chain of chemical reactions which will result in the development of a plant embryo

51. STEPS IN SEED GERMINATION
Water is added (most important)
Activates enzymes necessary for cellular respiration in the maturing seedling so it can produce the energy needed to grow
Seeds are exposed to heat
Chemical energy in seed’s starch is converted to glucose during germination
Seeds are exposed to light
Oxygen is available

52. Seed Germination
Radicle is first part of embryo to appear (develops into root)
Hypocotyl appears above soil (photosynthetic tissue)

53. SEED DORMANCY
Dormancy is the block of complete germination of a viable seed under favourable conditions
Advantage: Germination is delayed until conditions are favourable for the survival of both the seed and the maturing plant
Ex. Even though some conditions are favourable in late November, dormancy occurs due to the onset of winter.
Seed banks are a plant strategy to ensure that not all the seeds of one species germinate in a single year. This insurance save a species in the event of a catastrophic drought, extreme cold, etc.

54. Jigsaw
Each person take two techniques in artificial propagation and explain it to the class (pg )