Plants

1. Plants Chapters 23 - 26

2. Adaptations of Plants • On land, most plants take up nutrients from the soil, a challenge for early plants • To prevent water loss, early plants developed a cuticle, a waxy layer that covers the non-woody parts of most land plants • Stomata are pores on leaves that permit plants to exchange oxygen and carbon dioxide and regulate water loss. Guard cells are around each stomata, and allow it to open and close by swelling with water or losing water.

3. Adaptations of Plants • Larger, more complex plants have a vascular system, a system of tube-like cells that allow for the distribution of materials through out the plant • Developed in land plants • Plants with a vascular system are called vascular plants • Plants without a vascular system are called nonvascular plants

4. Parts of the Vascular System • Xylem: hard walled cells that transport water and minerals from the roots of the plant, upwards towards the shoots • Phloem: soft walled cells that transport organic nutrients down from the shoots towards the roots (translocation) • Xylem Up, Phloem Down! • The movement of water in a plant is driven by capillary action, transpiration and attraction of water molecules for one another.

5. Main Plant Parts Roots: the part of the plant that grows underground • Absorbs water and minerals • (Taproots vs Fibrous roots) • Also used to anchor the plant • Movement of water up to leaves is influenced by TRANSPIRATION – the release of water vapor into the air through the leaves • Root hairs: increase surface area for absorption of water and minerals • Root cap: hard portion of the tip of the root that protects the root from damage

6. Cross Section of a Buttercup Leaf • Vascular • Tissue Vascular Tissue Xylem Phloem

7. Shoots: composed of the stem and leaves of the plant • Supports the plant for growth • If you soak a celery stalk in red food coloring, it will absorb and make the xylem visible • Two types: woody and herbacious • Meristem: site of plant growth due to rapidly dividing cells in this location

8. Xylem Phloem

9. Leaves • Photosynthetic organ of the plant, used to convert sunlight into food • Trap light energy • Parts of Leaves • Stomata: pores within the leaf that open to let CO2 in and O2 and Water vapor out. • Guard cells open and close the stomata. • Cuticle: waxy covering on leaf that prevents water loss

12. Seeds • Seeds are plant structures that contain the plant embryo (a baby plant) • Vascular plants are seed plants • Seeds offer 4 benefits: • Protection by seed coat (keeps plant from drying out) • Nourishment (food supply) • Plant dispersal • Delayed growth

13. Seed

14. Flowers • Flowers are the reproductive structure of plants that produce pollen and seeds. • They are usually bright in color, and often have a fragrance in order to attract pollinators. • Reproductive organ of the plant • Flowers are usually both male and female • The male part of the flower is the STAMEN • The female part of the flower is the PISTIL • See your coloring sheet for more detail on flower anatomy

16. Non Vascular Plants • Have no vessels, stems, leaves or roots • Require water for reproduction • Examples: Mosses and liverworts

17. Classifying Plants: Vascular • Vascular plants: have vessels to transport food and water; they have roots, stems and leaves • Vascular system is comprised of both xylem and phloem • “xylem up, phloem down” • Examples: ferns, plants with cones or flowers

19. Ferns have fronds, which are the leaves of a fern or palm. • Cones are the reproductive structures for some plants

20. Gymnosperms • "naked seeds" • cone bearing plants (seeds grow on cones) • needle like leaves • usually stay green year round • Pollinated by wind  pollination: transferring of pollen from male to female cone • Examples: pine trees & evergreens

21. Angiosperms • Flowering plants • Seeds are enclosed in a fruit, a specialized structure that houses the seeds, provides protection, and helps with seed dispersal (animals eat fruit and carry the seeds away) • Most are pollinated by birds & bees • Have finite growing seasons • Examples: grasses, tulips, oaks, dandelions • Divided into two main groups: Monocots & Dicots

22. Monocots: a flowering plant that produces seeds with one seed leaf (cotyledon) • Dicots: flowering plants that produce seeds with two seed leaves

24. Plant Reproduction • Pollen is produced by the stamen and contains sperm. • Pollen moves away from the plant via the wind or other pollinators (birds & bees) • Pollination and Fertilization: The pollen lands on the pistil of another plant and fertilizes the eggs within the ovary which develops into a FRUIT that encloses the SEEDS. • GERMINATION occurs when a seed sprouts (usually caused by changes of temperature and moisture)

25. Plant Reproduction • The fruit itself plays a role in plant reproduction. • Provides food for other organisms • Protects the seed • Helps disperse the seeds

26. Environmental Factors that Influence Growth • Tropism: a response in which a plant grows either towards or away from a stimuli • Three Types Phototropism: response to light Gravitropism: response to gravity Thigmotropism: response to touch

28. Positive and Negative Gravitropism in Roots and Shoots

30. Environmental Factors that Influence Growth • Photoperodism: response of a plant to length of days and nights Long-day plants: flower when nights are short Iris Short-day plants: flower when nights are long Poinsettia

31. Environmental Factors that Influence Growth • Temperature: Affects production of fruit and flowers, growth of buds, dropping of leaves, and dormancy.