1. Plant Tissues

2. Sequestering Carbon in Forests
Human activities are increasing the amount of CO2 in the atmosphere exponentially, with potentially catastrophic effects on Earth’s climate
Plants remove CO2 from the atmosphere by photosynthesis and sequester it in their tissues
Carbon locked in molecules of wood and other durable plant tissues can stay out of the atmosphere for centuries

4. Wood
Carbon is a major part of cellulose and lignin that reinforce specialized cells and structures that allow a woody plant to grow tall
Figure 25.1 Wood. Wood’s porous structure (above) allows it to transport water and nutrients throughout the plant. Despite its porosity, wood is strong enough to support a plant body that can be hundreds of feet tall (opposite). Carbon that gets incorporated into sturdy plant tissues such as wood can stay out of the atmosphere for centuries.
Lignin is a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae

5. Organization of the Plant Body
Most flowering plants have aboveground shoots, including stems, leaves, and flowers
Most kinds also have below-ground roots
Monocots and eudicots differ in tissue organization

6. The Basic Body Plan
Pipelines inside stems conduct water, nutrients, and photosynthetically produced sugars between leaves and roots
Roots absorb water and dissolved minerals, and usually serve to anchor the plant; some plants have specialized root cells that store carbohydrates

7. Three Plant Tissue Systems
Ground tissue system
Makes up the bulk of the plant body
Stores materials, functions in photosynthesis, and structurally supports the plant
Vascular tissue system
Tubes distribute water and nutrients through a plant body
Dermal tissue system
Covers and protects the plant body
Includes simple and complex tissues

8. Body Plan of a Tomato Plant
Vascular tissues conduct water and solutes
Ground tissues make up the plant body
Dermal tissue covers root and shoot surfaces

9. Body Plan of a Tomato Plant
shoot tip (terminal bud)
lateral bud
node
flower
dermal tissues
vascular tissues
leaf
seeds
in fruit
withered seed leaf (cotyledon)
ground tissues
Vascular tissues (purple) conduct water and solutes. They thread through ground tissues that make up most of the plant body. Epidermis, a type of dermal tissue, covers root and shoot surfaces.
stem
shoots
roots
primary root
lateral root
root tip
Fig. 25.2, p. 398

10. Eudicots Versus Monocots
Tissues and other characteristics are organized differently in monocots and eudicots:
Seeds
Flowers
Leaves
Pollen
Vascular Bundles

11. Eudicots Versus Monocots
Monocots and eudicots are named after their cotyledons – leaf-like structures that contain food for a plant embryo
cotyledon
The primary leaf in the embryo or the “seed leaf”

12. Eudicot and Monocot Cotyledons
A Eudicots
In seeds, two cotyledons (seed leaves of embryo)
Fig. 25.4a.1, p. 399

13. In seeds, one cotyledon (seed leaf of embryo)
Eudicot and Monocot Cotyledons
B Monocots
In seeds, one cotyledon (seed leaf of embryo)
Fig. 25.4b.1, p. 399

14. Cotyledons

15. Flower parts in fours or fives (or multiples of four or five)
Eudicot Flowers
Flower parts in fours or fives (or multiples of four or five)
Fig. 25.4a.2, p. 399

16. Flower parts in threes (or multiples of three)
Monocot Flowers
Flower parts in threes (or multiples of three)
Fig. 25.4b.2, p. 399

17. Eudicot and Monocot Flowers

18. Leaf veins usually forming a netlike array
Eudicot Leaves
Leaf veins usually forming a netlike array
Fig. 25.4a.3, p. 399

19. Leaf veins usually running parallel with one another
Monocot Leaves
Leaf veins usually running parallel with one another
Fig. 25.4b.3, p. 399

20. Eudicot and Monocot Leaves

21. Pollen grains with three pores or furrows
Eudicot Pollen
Pollen grains with three pores or furrows
Fig. 25.4a.4, p. 399

22. Pollen grains with one pore or furrow
Monocot Pollen
Pollen grains with one pore or furrow
Fig. 25.4b.4, p. 399

23. Eudicot and Monocot Pollen

24. Vascular bundles organized in a ring in ground tissue of stem
Eudicot and Monocot Vascular Bundles
Vascular bundles organized in a ring in ground tissue of stem
Fig. 25.4a.5, p. 399

25. Eudicot and Monocot Vascular Bundles
Figure 25.4 Comparing some of the characteristics of A eudicots and B monocots.
Vascular bundles
throughout ground
tissue of stem
Fig. 25.4b.5, p. 399

26. Vascular Bundles

27. Monocot
Eudicot