Biol 156 Exam 1

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Biol 156 Exam 1
2010-09-28 04:25:54
Plant Growth Development Calderon

Plant Growth and Development Calderon
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  1. Auxins
    • Synthesized from L-tryptophan
    • Natural Auxin: IAA
    • Synthetic Auxin: NAA, IBA, 2-4-D
    • Synthesized in: Young leaves, primordia, & developing seeds
    • Effects: Cell enlargement, cell division, vascular tissue differentiation, root initiationand apical dominance.
  2. Cytokinins
    • Synthesized from: de novo form 5’ AMP (purines)
    • Natural cytokinin: Zeatin.
    • Synthetic cytokinin: BAP (N6-benzyl aminopurine).
    • Site of synthesis: Root tips and developing seeds.
    • Effects: Cell division and morphogenesis in tissue culture.
  3. Ethylene
    • Synthesized from: Ethylene is synthesized from methionine
    • Site of synthesis: Most tissues in response to stress and in tissue undergoingprogrammed cell death or ripening..
    • Effects: Release from dormancy, shoot and root growth and differentiation, leave and fruit abscission.
  4. Abscisic Acid
    • Synthesized from: ABA is synthesized from mevalonic acid.
    • Site of synthesis: Root and mature leaves.
    • Effects: Stomatal closure, inhibition of shoot growth, negative regulation the effectsof gibberellins on α-amilase synthesis in cereal grain germination.
  5. Gibberellins
    • Synthesized from: Gas are synthesized from geranylgeranyl diphosphate (GGDP).
    • Site of synthesis: Young tissue of the shoot and developing seeds.
    • Effects: Stem elongation, bolting in long day plants, induction of seed germination,induction of maleness in dioecious plants.
  6. Other Hormones
    • Brassinosteroids
    • Jasmonic acid
    • Salicylic acid
    • Polyamines
    • Systemin (peptide hormone)
    • ENOD40 (peptide hormone)
  7. Hormone Concentration & Growth
    There is a correlation between hormone concentration and internodal growth
  8. Hormone Sensitivity
    • S shaped curve
    • Low response to low hormones
    • Large response to more hormones
    • Slows down again in response to a lot of hormones
    • Could be result in change of receptor affinity
  9. Development
    The process of becoming
  10. Animal Development
    • Faithfully followed blueprint
    • Cell movement and gene expression
    • Not influenced much by outside environment
    • Single animal cell can only turn into entire animal up to certain point
  11. Plant Development
    • Always undergoing development
    • Develop according to genetic blueprint but greatly influenced by environment & mediated by hormones
    • Possibly due to lack of fixed development, differentiation is fully reversible
    • Totipotent
    • No gastrulation (cell migration)
    • Adult plant structures develop from meristems
    • Inability to move means plants had to evolve to handle fluctuating environments
  12. Meristems
    Can be used to regenerate entire plant
  13. Non-vascular Plants
    • No circulatory System
    • (stay small because no vascular system)
  14. Vascular Plants
    Have vascular system
  15. How long have land plants been around?
    475 million years
  16. How long have vascular plants been around?
    420 million years
  17. Unique Land Plant Adaptation
    • Waxy covering preventing desication
    • Present in land plants, not green algae
  18. Unique Land Plant Adaptation
    • Special cellular array to permit gas exchange
    • 4 cells working together (2 relax to open, tense to close)
    • Closed during day, open at night
  19. Unique Land Plant Adaptation
    Capturing CO2
    C3 & C4 (2 types of carbon molecules)
  20. Unique Land Plant Adaptation
    • Use organic molecules to capture and bind CO2 while stomata is open
    • Close stomata when full
    • Most desert plants are CAM
  21. Unique Land Plant Adaptation
    Multicellular Sex Organs
  22. Male Gametangia
    • Antheridium
    • Produces sperm
  23. Female Gametangia
    • Archegonium
    • Single egg
  24. Where do fertilized eggs develop into multicellular embryos?
    Within the archegonium
  25. Alternation of Generation
    Homosporous (1 type of spore)
    Alternate between mitosis and meiosis

    Fertilization-> Sporophyte (2n) -> Spore Mother Cells -> Meiosis -> Spore (1n) -> Mitosis -> Gametophyte (1n) -> Male & Female
  26. Sporophyte
    Diploid multicellular organism (most of plant)
  27. Gametophyte
    Haploid multicellular organism (flower)
  28. Heterosporous Reproduction
    Each spore produces male OR female

    1. Sporophyte (2n) -> Megasporangium -> Megaspore Mother Cells (in ovule) -> Meiosis -> Megaspore -> Female gametophyte (1n) -> female

    2. Sporophyte (2n) -> Megasporangium -> Microspore Mother Cell (in anther) -> Meiosis -> Microspore -> Male gametophyte (1n) -> male
  29. Double Fertilization
    Zygote -> Embryo (in seed)

    3n Endosperm (in seed) serves as nourishment for seed
  30. Meiosis of Microspores
    Become 2 cell haploid polingrain
  31. Meiosis of Megaspores
    Divide 3 times to become 7 cells with 8 nucleii (embryo sac)

    One central cell has 2 nucleii and gets fertilized to produce the endosperm which is 3n
  32. Dicots
    • 2 Cotyledons
    • Netted veination in leaves
    • Vascular bundles in circles
    • Taproot system
  33. Monocots
    • 1 Cotyledon
    • Parallel veination in leaves
    • Scattered vascular bundles
    • Fibrous root system