1. 3.02 Discuss the anatomy and functions of plants
B. Plant Physiology
3.02 Discuss the anatomy and functions of plants

2. Six Major Plant Parts
Roots
Stems
Leaves
Flowers
Fruit
Seeds

3. Leaves – External Parts
Petiole
leaf stalk or part that connects leaf to stem.
Midrib
Large central vein of the leaf

4. Leaves – External Parts
Blade
the large, flat part of a leaf.

5. Leaves – External Parts
Veins
the structural framework of a leaf.

6. Leaves – External Parts
Margin
the edge of the leaf.
There are several different styles (draw these)
Entire
Serrated
Lobed
Crenate
margin

7. Leaves – External Parts
Apex
leaf tip
apex

8. Leaves – Internal Parts
Upper and lower epidermis
skin of the leaf that prevents the loss of too much moisture.

9. Leaves - Internal Parts
Stomates
small openings under the leaf for breathing or transpiration.

10. Leaves – Internal Parts
Guard cells
opens and closes the stomata.

11. Leaves – Internal Parts
Chloroplasts
small green particles that contain chlorophyll, gives leaves their green color and are necessary for photosynthesis.

12. Functions of the Leaf
Photosynthesis is a process by which plants capture sunlight and use it to convert carbon dioxide and water into food
Respiration converts sugars and starches into energy
Transpiration is the release of water vapor from the leaves of plants
It also cools the plant

13. Leaves – Additional Notes
Sessile
leaves with no petiole.
Sessile

14. Leaves – Additional Notes
Bracts
modified leaves usually found on a poinsettia.

15. Leaves – Additional Notes
Needles and scales
Modified leaves found on a pine tree

16. Leaves – Additional Notes
Glabrous
Leaves or stems have a smooth, non-hairy feel
Southern Magnolia

17. Leaves – Additional Notes
Pubescent
Leaves or stems have a hairy feel
African Violets

18. Stem – External Parts
Lenticels
breathing pores.

19. Stem – External Parts Bud scale scar
shows where the terminal buds were located the previous year.
Bud scale scar

20. Stem – External Parts
Leaf scar
shows where leaves were attached.

21. Stem – External Parts Terminal bud bud at the end or tip of the stem.
terminal buds

22. Stem – External Parts
Axillary bud
Bud located at the axil of the leaf

23. Stem – External Parts Lateral bud bud on the side of the stem.

24. Stem – Internal Parts Xylem Phloem Cambium
tissue that transports water and nutrients up from roots to stems and leaves.
Phloem
tissue that transports food down from the leaves to the roots.
Cambium
thin, green actively growing tissue located between the bark and wood and produces all new stem cells.

25. Monocot Stem: Vascular Bundles
Stem – Internal Parts
Xylem
Heartwood
Monocot Stem: Vascular Bundles
Cambium
Bark
Phloem
Dicot Stem: Layers

26. Stem – Internal Parts
Bark
Old inactive phloem
Protection for the stem

27. Stem – Internal Parts
Heartwood
Old inactive xylem.

28. Stem – Internal Parts
Sapwood
New active xylem.

29. Stem Structure - Cotyledons
Monocot ~ one seed leaf
Plant stems that have vascular bundles that contain both xylem and phloem in each bundle.
Examples: grasses, corn
Dicot ~ two seed leaves
plant stems have phloem layer and a xylem layer separated by cambium.
Examples: trees

30. Vascular Bundles - Monocots
Phloem
Xylem
Top View

31. Functions of the Stem
Translocation is the movement of water and minerals through the plant
The phloem moves food down from the leaves to the roots
The xylem moves water and nutrients up from the roots to the leaves
Supports the branches of the plant

32. Root – External Parts Root cap Root hairs
Located at the tip of the root and is where new cells are produced
Root hairs
absorb moisture (water) and minerals.

33. Root – External Parts Phloem Xylem
the outer layer and carries food down the root.
Xylem
the inner layer and carries water and minerals up to the stem.

34. Types of Roots
Fibrous
many branched shallow roots. They are easier to transplant.

35. Types of Roots
Tap
long root with few branched ones, are more difficult to transplant.

36. Functions of the Roots Anchor the plant and hold it upright.
Absorption – take water and nutrients from the soil and conduct them to the stem.
Asexual reproduction.
Store food for plant use.

37. Flowers Flowers develop into seeds and fruits.
External Parts of the Flower
Sepals
green parts that cover and protect flower bud before it opens.
Petals
are really leaves that are modified to attract insects for flower pollination, the pretty part that we call flowers.

38. Flowers – External Parts
petal
sepal

39. Stamen - Male Parts of the Flower
Anther
a sac like structure that contains pollen, the male sex cells.
Filament
short stalk that holds up the anther
anther
filament

40. Pistil – Female Parts of the Flower
Stigma
sticky part on top of style where insects leave pollen.
Style
holds up the stigma and connects it to the ovary.
Ovary
if fertilized becomes a fruit or seed coat.
Ovules
the eggs or female sex cells that become seeds if fertilized.

42. Functions of the Flower
1. Attracts insects for pollination.
2. Produces seeds for sexual propagation.
3. Produce fruit to protect, nourish and carry seeds.

43. Flower Complete flower Incomplete flower Fertilization Pollination
has both male and female parts.
Incomplete flower
has only male or female parts.
Fertilization
When pollen travels down the style, joining the sperm and the ovule
Pollination
The transfer of pollen from the anther to the stigma
Cross pollination
transfer of pollen from the stamen to the stigma of one flower to a flower on another plant.
Self pollination
transfer of the pollen to the stigma of a flower on the same plant.

44. Flower Additional Notes
Corolla
all auxiliary part of the flower not including reproductive organs.
The collective term for all petals of a flower.
Calyx
the external usually green or leafy part of a flower. The collective term for all sepals of a flower.
Receptacle
the enlarged tip of a stem on which a flower is born.

45. Flower – Additional Parts
receptacle
calyx

46. Additional Information
The fruit serves as protection for the seeds
The function of the fruit is to help with seed dispersal