PLANTS

1. PLANTS • Parts • Clasification • Reproduction

2. Parts of a Vascular Plant • vertical axis • Underground: root to absorb water and ions and anchor • above ground: shoot: • stem serves as a framework for positioning the leaves • Leaves: photosynthesis takes place • growth zones: unspecialized cells called meristems

3. Tissue Types • Dermal: • outer protective covering • covered by a waxy layer called the cuticle, effective barrier against water loss • Vascular: 2 types • Xylem • water and minerals pass from the roots to the shoots, when water reaches the leaves, most exits through the stomata • Phloem • principal food-conducting tissue

4. 1. Roots • Main Roots have: • central column of xylem • alternating are strands of phloem • surrounding the central column, a cylinder of cells called pericycle: branch or lateral roots form from

5. A root cross section

6. 2. Stems • Growth: • Primary: leaves appear while the apical meristem elongates • Secondary: differentiation of the vascular tissue • vascular tissue types: • dicots, vascular bundles (xylem and phloem) are around the outside of the stem • monocots, vascular bundles are scattered throughout

7. places of the stem where leaves form are called nodes • portions of the stem between these leaf attachment points are called internodes

8. source of economically important product: wood • is accumulated xylem • displays rings based on the growth rate differences: cambium divides more actively in the spring and summer • bark (periderm): all of the tissues of a mature stem outside of the vascular cambium including the cork

9. 3. Leaves • Growth:marginal meristems which grow outward and ultimately form the blade (the flattened portion) of the leaf • leaf veins, comprised of xylem and phloem, run through the leaf • dicots, the veins have a net or reticulate venation • monocots, the veins are parallel

10. Water Movement • factors: • initial movement of water into the roots: osmosis • fluid in the xylem contains more solutes than the surroundings • capillary action adds “pull” to the movement of water up • A final “pull” is transpiration, water evaporating from the top (leaf) of the tube pulls the column of water up • the column of water does not collapse because water molecules are attracted to each other • the narrower the diameter of the tube, the more tensile strength, or resistance to separation, of the water column

12. Plant Classification • complex multicellular organisms • Autotrophs, feed themselves by photosynthesis • almost exclusively on land • dominant organisms on the surface of the earth

13. Plant Evolution • ancestor probably: green algae • Four key evolutionary advances: • alternation of generations, • vascular tissue, transports water and nutrients and provides support • Seeds, provide nutrients and protection for the plant embryo until it encounters favorable growing conditions • flowers and fruits, facilitated fertilization and dispersal of their seeds

14. 1. Nonvascular Plants • size limited • materials transported by osmosis and diffusion • mosses

15. 2. Seedless Vascular Plants • ferns • sporophyte generation is much larger and complex

16. Vascular Tissue • specialized cylindrical or elongated cells that form a network throughout a plant

17. 3. Vascular, Seed Plants • Seed: crucial adaptation to land to protect the embryonic plant • produce two kinds of gametophytes: • develop within the sporophyte • male: pollen grains • female: egg within an ovule • gymnosperms • ovules are not completely enclosed • angiosperms • ovules are completely enclosed

18. Gymnosperms • Conifers, • seeds in cones • most needle-like leaves • Cycads, • palmlike leaves • Ginkgo, • fan-shaped leaves

19. Angiosperms: flowers • 90% all living plants • Embryos store food reserves in seed leaves or cotyledons • monocotshave one cotyledon • dicotshave two cotyledons

20. Angiosperm Reproduction • sexual • Asexual

21. Asexual, vegetative reproduction • new individuals are cloned from parts of the parent • Samples: • Runners, stems growing along the soil • Rhizomes, underground horizontal stems

22. Sexual reproduction: alternation of generations • male gametophytes: pollen grains • female gametophyte: embryo sac

23. Flowers • Base: receptacle • four concentric circles: 1. Sepals, protect 2. Petals, attract pollinators 3.male parts: stamens, anther with the pollen grains 4.female parts:ovules in the bulging base called ovary, a stalk style, sticky tip stigma to receive the pollen

24. different kinds of flowers: because insects and plants coevolved • insects specialize in visiting particular kinds of flowers • Birds also pollinate some flowers, especially red ones

25. Formation of pollen and egg • Eggs develop in the ovules • each ovule contains a megaspore mother cell that undergoes meiosis to produce four haploid megaspores, only one survives to undergo repeated mitotic divisions that produce eight haploid nuclei

27. Pollination • process by which pollen is transferred from the anther to the stigma • gymnosperms, pollen is dispersed by wind; species must grow close, flowers are small, green, and odorless • angiosperms use animals to carry pollen from flower to flower and are rewarded with food; e.g.,nectar

28. Pollen grains adhere to the surface of the stigma and begin to grow a pollen tubeuntil it reaches the ovule in the ovary, entry to the embryo sac • it releases two sperm cells: double fertilization • one sperm fertilizes the egg • the other sperm goes on to form endosperm

29. Seed • three parts • embryo • endosperm, a source for food for the developing embryo (cotyledons) • a drought-resistant protective cover

30. Seeds improved the adaptation of plants to living in land: • Dispersal into new habitats • Dormancy and Germination, plants postpone development until conditions are favorable • Nourishment; provisions the seed during the critical period just after germination

31. Fruits • Is a mature ripened ovary containing fertilized seeds • angiosperms use fruits to have animals aid in the dispersal of seeds; although eaten the seeds are resistant to chewing and digestion passing out with the feces and ready to germinate

32. Types of fruits and common modes of dispersion

33. Practice questions 1. Growth in vascular plants is regulated and coordinated by: • photosynthetic tissue • root tissue • meristematic tissue 2. In vascular plants, phloem tissue transports _______ 3. In stems, the tissue responsible for secondary growth is the: • Collenchyma • Pith • Cambium • cortex

34. 4. One difference between monocot/dicot plant stems is the: • absence of buds in monocots • organization of vascular tissue • presence of guard cells 5. Which of the following is not a process that directly assists in water movement from the roots to the leaves? • photosynthesis • root osmotic pressure • capillary action • transpiration 6. Sexual reproduction in angiosperms requires male _______

35. 7. The flower shape, scent, color, nectar in the flowers of some angiosperms are related to the plant's __ 9. Fruit forms from a flower's: • Ovary B) sepals C) carpels D) stigma 10. Which of the following structures does not give the plants an evolutionary advantage? A)chloroplasts B)vascular tissue C)seeds D)flowers 11. Mosses do not reach a large size because ------------ 12. One characteristic that separates ferns from more complex vascular plants is that ferns do not have ---------

36. 13. What separates the gymnosperms from the rest of the vascular plants is: • a vascular system • ovules completely covered • ovules not completely covered • fruits and flowers 14. What separates the angiosperms from the rest of the vascular plants is: • a vascular system • ovules completely covered • ovules not completely covered by the sporophyte • fruits and flowers 15. Flower shape and color can be linked to the process of ------------- 16. If the seeds of a plant are encased in a fleshy fruit, then the most likely form of dispersal is: • to attach to an animal's fur or skin • Wind • an animal's digestive system and processes • water