Plant Kingdom Part II Advanced Plants

1. Plant Kingdom Part IIAdvanced Plants

2. Advanced Plants are generally plants that have evolved within the last 300 million years, utilize seeds for reproduction and are economically important for mankind for needed food and materials. Primary Plant Structures a. Roots b. Stems c. Leaves

4. Roots • Are underground structures that draw water and minerals into the plant by osmotic pressure. • May be tap roots, fibrous roots or support roots. • Are made up of a center core of vascular tissue called the cortex and a thin outer surface called the epidermis. • The epidermis may also contain finer root hairs for increased surface area • Stores starch for a food reserve • Is an active area for plant growth • Area of Primary growth toward gravity and water sources. (geo-trophism and hydro-trophism)

6. Stems • Connect the root system of the plant to the leaves of the plant • Contain two types of conducting tissue. • Xylem- moves water and dissolved minerals upward through the plant. • Phloem- moves organic compounds (glucose) fom the leaves downward toward the roots. • May be Herbaceous or Woody depending on the amount of cellulose in the stem. • Vascular patterns may be ringed or random bundles. • Stem growth is more outward called secondary growth. • In woody stems, the active vascular tissue is just under the bark and outside the dense cambium of the inner plant. • Ends of the stems are also areas for primary growth and tend grow toward light (photo-trophism)

9. Leaves • The specialized structure where most of a plant’s Photosynthesis occurs. • Leaves come in many shapes, sizes and may be evergreen or deciduous. • Generally leaves are broad to capture a maximum amount of sunlight. • The cross section of a leaf reveals the following structures

10. a) Upper epidermis- cuticle- waxy outer covering of the leaf b) Mesophyll- cells that are long and column like cells called the palisade layer and shorter cells called the spongy layer. Through out the Mesophyll are veins that are made up of xylem and phloem cells. Chloroplasts in the Mesophyll contain chlorophyll, a photosynthetic pigment. c) Lower epidermis- where stoma and guard cells regulate gas and water exchange with the outside air.

12. Advanced Plant Reproduction • In advanced Plants, reproduction adapted to a drier environment where water wasn’t as plentiful. • Pollen replaced Sperm as the male gamete • Alternation of Generation ended in favor of a large Sporophyte that produced Spores, that then quickly undergo Meiosis to produce Pollen and Egg. • In Gymnosperms, the fertilized zygote (seed embryo ) is housed in a female cone. • In Angiosperms the fertilized egg (seed embryo) is housed in dry or fleshy fruit.

13. Life Cycle of the Gymnosperms

14. Life Cycle of a Typical Angiosperm

15. Structure of a Typical Flower

16. Plant Pigments • Chlorophyll- includes types • A-green found in land plants only • B-green found in land plants and algae • C-green found in algae and protists like diatoms • Carotenes- orange and yellow but are accessory pigments b/c they send energy to green chlorophyll first. Includes fucoxanthin (brown) • Phycobilins-includes cyanin (blue) and erythrin (red)

17. Plant Hormones • 5 Primary Plant hormones to know • Auxin- cell elongation • Gibberellins- cell elongation • Cytokinin- cell division • AbscisicAcid- growth inhibitor • Ethylene- fruit ripening

18. Trophism- the tendency for a plant to grow toward a stimulus • Phototropism- toward light • Geotropism (Gravitism)- toward gravity • Thigmotropism- toward solid objects • Hydrotropism- toward water

19. Monocots and Dicots • Within Angiosperms, there are two divisions of Plants, Monocots and Dicots. • Monocotyledons are plants that include grasses, lillies, orchids, yuccas and other blade leaf plants. The name comes from the single leaf produced by the plant embryo • Dicotyledonsare plants that include most vegetable plants and broad leaf fruit and nut trees. The name comes from the two seed leaves produced by the plant embryo

20. Other Monocot and Dicot characteristics

22. Plant Taxonomy (seedless nonvascular) • Bryophyta- • Hepatophyta- • Anthocerophyta-

23. Plant Taxonomy (seedless vascular) • Pterophyta- • Lycophyta- • Sphenophyta- • Psilophyta-

24. Plant Taxonomy (Seeds in cones and vascular) • Coniferophyta- • Cycadophyta- • Ginkgophyta- • Gnetophyta-

25. Plant Taxonomy (seeds from flowers and vascular) • Anthrophyta (Angiosperms) • Monocotyledons- • Dicotyledons-