1. Plant Structure, Growth, & Development

2. The Diversity of Angiosperms Angiosperms (flowering plants) can be divided into 2 major categories:  Monocots – have one seed leaf (cotyledon)  Dicots – have 2 seed leaves (cotyledons)

3. Monocots Monocots have only 1 cotyledon (seed leaf) Examples of monocots:  Corn, wheat, lilies, orchids, palms

4. Dicots Dicots have 2 cotyledons (seed leaves) Examples of dicots:  Roses, clover, tomatoes, oaks, daisies

5. Woody vs. Herbaceous Plants Angiosperms can also be subdivided into the groups of woody and herbaceous plants  Woody plants are made of cells with thick cell walls that support the cell body Examples: trees, shrubs, vines  Herbaceous plants do not produce wood as they grow, and instead have smooth stems Examples: dandelions, sunflowers

6. Plant Life Spans Most plants experience indeterminate growth  They continue to grow as long as they live The lifespan of plants, however, is genetically determined  Annuals – complete their life cycle in 1 year Examples: marigolds, cucumbers (lots of garden plants)  Biennials - complete their life cycle in 2 years Year 1: germinate & grow roots Year 2: grow stems & leaves, produce flowers & seeds Examples: evening primrose, celery  Perennials – live for more than 2 years Examples: Maple trees, grasses, palm trees

7. Plant Structure Plants are made up of a root system and a shoot system

8. The Root System What do roots do?  Anchor the plant in the soil  Absorb minerals and water  Store food Types of root systems  Fibrous root system Found mostly in monocots  Taproot system Found mostly in dicots

9. How do roots grow? There are 3 distinct zones in a plant root where different things are taking place  Zone of cell division Includes the apical meristem Produces new cells by mitosis  Zone of elongation Cells get longer  Zone of maturation The cells differentiate and become specialized The root is protected by a root cap, which protects the apical meristem as the plant grows down into the soil

10. The Shoot System The shoot system consists of:  vegetative shoots (which bear leaves)  floral shoots (which bear flowers) Stems have 3 important functions:  Producing leaves, flowers, branches  Holding leaves up to the sunlight  Transporting substances between roots and leaves

11. How do stems grow? Primary growth  Increase in length  Occurs by cell divisions in apical meristem (at top of shoot) Secondary growth  Increase in width  Occurs by cell divisions in the lateral meristems (also known as vascular cambium)

12. Apical Meristems

13. The Shoot System: Leaves Leaves are attached to stems at nodes The area between 2 nodes is called an internode

14. The Shoot System: Leaves Leaves are the primary photosynthetic organs of most vascular plants Most leaves have a flattened blade and a petiole, which is the stalk that attaches the leaf to the stem

15. Tissue Systems in Plants All 3 plant organs (root/stem/leaf) have dermal, vascular, and ground tissue systems Dermal Tissue System  Outer protective covering, similar to our skin  Protects the plant from water loss and disease  The cuticle is a waxy coating that helps to prevent water loss

16. Tissue Systems in Plants Vascular Tissue System  Carries out long-distance transport of materials within the plant  Xylem and phloem are examples of vascular tissues Ground Tissue System  Pith (inside vascular tissue) and cortex (outside vascular tissue) are examples of ground tissue  Includes cells specialized for storage, photosynthesis, and support

17. Flower Structure Flowers are the reproductive structure of angiosperms Sepals:  Enclose the bud before it opens  Protect flower while it’s developing Petals:  Usually brightly colored to attract pollinators

18. Flower Structure Stamens:  The male portion of a flower  Made up of an anther and a filament  The anther produces haploid pollen grains by meiosis  Most flowers have multiple stamens

19. Flower Structure Carpels/Pistils:  The female portion of a flower  Stigma: Sticky – to trap pollen  Style: Hollow tube which connects stigma and ovary  Ovary: Produces female gametes (ovules)

20. Monoecious and Dioecious Species of Plants Monoecious  “one house”  Has both male and female flowers on a single plant Dioecious  “two houses”  Male and female parts are found on separate plants