Biology Exam 4

  1. Fragmentation
    Can be an artificial process (cuttings) or natural process
  2. Runners
    horizontal stems that can lead to completely new plants
  3. Asexual reproduction
    natural cloning where all the offspring are genetically identical to the parent plant
  4. Sexual Reproduction
    produces offspring combine the genes from 2 parents and are genetically different from their parents
  5. Sporophyte
    diploid plant which produces haploid spores
  6. gametophyte
    • haploid plant which produces gametes
    • In mosses and fern, they are small and independent
  7. What is essential for sexual reproduction?
    Water
  8. In gymnosperms and angiosperms (seeded plants) - what about gametophyte and sporophyte?
    The gametophyte is very small and relies on the sporophyte and it is a par of the sporophyte.
  9. 2 types of spores in flowering plants
    • Hetersporous
    • Megaspores - gives rise to the female gametophyte
    • Microspores - gives rise to the male gametophyte
  10. Female gametophyte
    embryo sac containing an egg cell
  11. male gametophyte
    a pollen grain (sperm)
  12. zygote
    develops into the seed, which will form into a new sporophyte
  13. Stamens
    male reproductive part and consist of the filaments (stalk) which hold the anther
  14. Anther
    contains the pollen grains (male gametophyte)
  15. Carpel
    • female reproductive part
    • vase shaped structure made up of the stigma, the style, and the ovary
  16. Stigma
    • at the top of the carpel
    • sticky structure designed to catch the pollen
  17. Style
    • the neck of the carpel
    • pollen must "grow" through the style to reach egg
  18. Ovary
    • at the bottom of the carpel
    • contains the ovules which become seeds and the outer layers of the ovary becomes the fruit
  19. incomplete flowers
    lack one or more of the 4 floral parts
  20. Microspores (mother cells)
    develops inside the pollen sac
  21. Integument
    • outer layer of ovule
    • tissue is diploid
  22. formation of female gametophyte
    • 1) megaspore mother cell develops within the ovule
    • 2) megaspores divides by meiosis to form 4 haploid megaspore
    • 3) 3 of the 4 megaspores degrade
    • 4) the remaining one of the 4 goes through 3 rounds of mitosis but not cytokinesis which results in 8 nuclei in one cell
    • 5) the nuclei are distributed 3 on each en of the megaspore and 2 in the center.
    • 6) cytokinesis occurs forming 7 cells
    • 3 cells on each end of the embryo sac (one is the egg)
    • one larger central cell with 2 polar nuclei
  23. Primary endosperm cell
    larger center cell
  24. Pollination
    • starts when pollen from an anther lands on a stigma
    • pollen grain grow a tube down through the style towards the ovary
    • 2 sperm cells from the generative cell move down the tube to teh ovary where a double fertilization occurs
  25. Double Fertilization
    • one sperm fuses with the egg cell to form the zygote
    • the other sperm fuses with the polar nuclei in the primary endosperm cell making this triploid endosperm (3 set of chromosomes) tissues
  26. 3 parts of embryo
    • hypocotyl
    • epicotyl
    • cotyledons
  27. Dicots embryo parts
    Monocots embryo parts
    • 2 cotyledons in the embryo
    • 1 cotyledon
  28. Coleoptile
    a tough sheath that protects the cotyledon in monocots
  29. Wind pollinated flowers
    • inconspicuous and unscented
    • produces LOTS of pollen because of it low probability of a hit for an individual pollen grain (oaks and maples)
  30. Animal pollinated flowers
    • attract animal pollinators
    • frustrate undesirable visitors
    • ensure cross-fertilization
  31. 4 types of dispersal
    • wind dispersal
    • mechanical dispersal
    • water dispersal
    • animal dispersal
  32. What are the stimuli that plants receive from their environment?
    • Direction of gravity
    • Direction, intensity, and duration of sunlight
    • Strength of the wind
  33. Phototropism
    • the bending of plants towards sunlight
    • first plant respond discovered and the studied by Charles and Francis Darwin.
  34. Darwins experiments
    • region below the tip of grass coleoptile bends towars light
    • covering the tip with an (dark) opaque cap stops the bending
    • covering the bending region does not stop the bending
  35. Peter Boysen-Jensen
    • discovered the mechanism of the bending
    • tip cut off, elongation and bending is stopped
    • tip is replaced, elongation and bending is restored
    • if a porous gelatin slab is between the severed tip and shoot, elongation and bending is restored















    • If the tip of the plant was
    • cut off, then the elongation and bending is stopped.



    • If the tip of the
    • coleoptile was replaced, then the elongation and bending is restored.



    • If the replaced tip of the
    • coleoptiles had a porous gelatin slab between the severed tip and shoot, then
    • the elongation and bending is restored.



    • If the replaced the tip of the coleoptiles had a thin layer of non-porous
    • mica between the severed tip and shoot, then the response to light remained
    • blocked



















    • If the tip of the plant was
    • cut off, then the elongation and bending is stopped.



    • If the tip of the
    • coleoptile was replaced, then the elongation and bending is restored.



    • If the replaced tip of the
    • coleoptiles had a porous gelatin slab between the severed tip and shoot, then
    • the elongation and bending is restored.



    • If the replaced the tip of the coleoptiles had a thin layer of non-porous
    • mica between the severed tip and shoot, then the response to light remained
    • blocked
  36. Hormones
    chemicals produced in one location and transported to other regions where they exert specific effects
  37. Abscisic Acid
    • inhibitory hormone
    • causes stomata to close when water scarce
    • maintains dormancy in buds and seeds in bad weather by inhibiting the action other hormones especially gibberellin
  38. Auxins
    • regulate plant responses to light (phototropism) and gravity (geotropism)
    • promote cell elongation in shoots
    • prevent growth of lateral buds
    • in roots : low concentrations stimulate elongation, higher concentrations inhibit elongation, stimulate root branching
    • stimulate fruit development
  39. Statoliths
    mediated the bending due to gravity
  40. Gibberellins
    • promote cell elongation in stems
    • stimulate flowering, fruit development, seed germination, and bud growth
  41. Cytokinins
    • promote cell division including lateral meristems
    • stimulate overall metabolism, delaying the aging of leaves
  42. Ethylene
    • gaseous hormone
    • causes fruit to ripen
    • causes breakdown of cell walls in abscission layers: allowing leaves fruit and flowers to drop off at appropriate times
  43. Homeostatsis
    tendency of life to try and maintain the structure and regulate the internal environment
  44. Negative feedback
    a change in one direction causes a series of events in the other direction to counteract the change
  45. 3 components of negative feedback
    • set point - hypothalamus
    • sensors - points throughout body
    • effectors - shivering, faster metabolism, restrict blood to body's surface
  46. Positive feedback
    initial change in one direction sets off a series of events that intensifies a change in that same direction
  47. Tissue
    • composed of cells with similar structure and function or non-cellular components made by the cells (bone and cartilage)
    • Epitelial
    • connective
    • Muscle
    • Nerve
  48. Epithelial Tissue
    • cells form continuous sheets called membranes
    • forms a barrier because it has no blood vessels
    • nourished by diffusion from capillaries beneath it or is continuously lost and replaced by cell division
  49. Exocrine glands
    • glands remain connected to epithelial tissue and secrete material either outside that body or into a cavity
    • salivary, sweat, and sebaceous glands
  50. Endocrine glands
    glands have lost their connection to the epithelial tissue and secrete material into the bloodstream
  51. Connective tissue
    • includes the layer beneath the skin called the dermis, tendons, ligaments, cartilage, bone, fat, blood and lymph
    • surrounded by large quantities of extracellular substances that are secreted from the connective tissue
  52. Dermis
    responsible for nourishing the epithelial via capillaries and fluid-filled spaces
  53. Tendons and ligaments
    contain densely packed collagen fibers in a parallel arrangement
  54. Cartilage
    • covers ends of bones at joints
    • supports respiratory passages
    • supports ear and nose
    • forms shock-absorbing pads between vertebrae
  55. bone
    resembles cartilage hardened by deposits of calcium phosphate
  56. Fat cells (adipose tissue)
    specially modified to act as storage sacs for triglycerides
  57. Muscle tissue
    • specialized for contraction
    • made up of cells that contain actin and myosin filaments proteins
  58. 3 types of muscle
    • skeletal (straited)
    • smooth
    • cardiac
  59. Nerve tissue
    composed of neurons (specialized to generate and conduct electrical signals)
  60. 4 parts of neurons
    • dendrites - receive signals
    • cell body - maintains and repairs the cell
    • axon - conducts electrical signal to target cell
    • synaptic terminals - transmits the signal to target cell at a region call the synapse
Author
erica1114
ID
49834
Card Set
Biology Exam 4
Description
Plants, Tissue
Updated