Plants as Living Organisms

1. Plants as Living Organisms Plant and Soil Science

2. The Plant Kingdom • Plants are found in biomes from the tundra to the desert. • Four Major Groups of plants: mosses, ferns, gymnosperm, and angiosperm. • Gymnosperm: produce plants that produce seeds on the scales of cones. • Ex. Pine, spruce, fir

3. The Plant Kingdom • Angiosperm: Flowering plants • Ex. Corn, wheat, apples, petunias, oak • Two Classes • Monocots: send up a single cotyledon • Long narrow blades, with parallel veins, flowers in multiples of three, vascular bundles are scattered • Dicots: send up two cotyledons • Broad leaves, netted veins, vascular bundles in a circle, flowers in fours or fives

4. The Plant Kingdom- Life Cycles • Life Cycle: the time from when a plant begins growing until it dies • Annual: germinates, grows, and reproduces in one year. • Biennial: two growing seasons, first year they grow, second year they reproduce.

5. The Plant Kingdom- Life Cycle • Perennial: life cycle of two or more years • Herbaceous: soft shoots that are killed by frost. Send up new shoots in the spring • Woody: trees, shrubs, and vines above ground that survive winter • Hardy: how tolerant to cold a plant is

6. Structures- Roots • Function: • Absorb water and minerals from soil • Anchor plant • Store food

7. Structures- Roots • Most roots found in top 2 feet of soil • Primary root (radical) is the first root put out by the plant • Root hairs are near the growing tip of the root and increase surface area for absorption.

8. Structures- Roots • Root Systems • Tap Root • Thick main root that grows straight down • Can work for storage • Ex. Carrots, beets, and radishes • Fibrous Root • Branching slender roots • Less tolerant of dry conditions • Hold soil in place, and prevents erosion

9. Structures- Roots

10. Structures- Roots • Secondary roots: branch off the primary root • Root cap: tip of root, protects root from soil as the root grows

11. Structures- Stems • Function: • Hold leaves upright • Conduct water and minerals • Conduct food • Store food

12. Structures- Stems • Conducting food and water • Two types of conductive tissue- Xylem and Phloem • Xylem • Transports water from the roots up to the leaves • Phloem • Transports food to the roots and other parts of the plant

13. Structures- Stems/ Buds • Buds- contain undeveloped leaves, stems, or flowers. • Bud scales protect the bud. • Terminal bud: large tip of the twig, the growing tip, contains the apical meristem • Apical meristem is the primary growing point • Lateral buds are located along the sides of the branch

14. Structures- Modified Stems • Some stems have been modified for food storage and underground growth • Bulbs, corms, rhizomes, and tubers are all examples of modified stems

15. Structures- Modified Stems • Bulbs- tulips and onions, have scales

16. Structures- Modified Stems • Corms- Gladiolus and crocus, fleshy and scale covered

17. Structures- Modified Stems • Rhizomes- underground stem that produces branches, irises and lily of the valley

18. Structures- Modified Stems • Tubers- storage organs, potatoes and caladium

19. Structures-Leaves • Responsible for food production • Photosynthesis • Transpiration

20. Structure-Leaves • Comprised of specialized cells • Epidermis-protective layers • Cuticle-waxy coating • Stomata-pores allowing O2, CO2, and H2O exchange • Guard cells-controls stomata (xylem and phloem)

21. Structure-Leaves • Photosynthetic tissues • Mesophyll- “Middle of the leave” • Bulk of Photosynthesis • Palisade layer • Spongy layer

22. Structure-Leaves Broadleaf Plants- wide flat leaves • Simple leaves • Single leaf blade and petiole • Compound • Petiole, 2 or more leaves called leaflets

23. Structure-Leaves Narrow leaf plants- needle or scale shape leaves • Deciduous • Looses leave in Fall • Evergreen • Keep leaves year round

24. Structures- Flowers

25. Structures- Flower • Female- Pistil • Stigma- Top sticky portion to catch the pollen • Style-Tube that carries the pollen to the ovary • Ovaries-Where the seed will develop

26. Structures- Flower • Male- Stamen • Anther- Holds pollen • Filament- Holds the anther • Pollen- Male gamete

27. Complete VS. Incomplete • Complete Flower- • Male and female flower on one flower. • Able to Self Fertilize • Incomplete Flower- • Male OR Female Flower. • Must have both to pollinate • Can be on the same plant or on different gender plants.