PLB 407

  1. Geological time divisions are based on:
    mass animal extinction, usually marine animals
  2. Main subdivisions of paleontology
    • Invertebrate
    • Vertebrate
    • Plants
    • Palynology (pollen and spores of land plants)
    • Micropaleontology (marine plankton)
  3. Index fossils and criteria for good index fossils
    • -Index fossils are used to correlate strategraphic levels of rocks from one area to another
    • -Good index fossils are:
    • 1. common
    • 2. distinct morphologically
    • 3. have a wide geographic distribution
    • 4. have a narrow time distribution
  4. Direct vs. Indirect fossils
    • - Direct fossils are body fossils, typically "hard parts" such as shells and bones
    • - Indirect fossils are traces of animals like footprints
  5. Paleobiology
    Integration of plant, animal, and other biotic evidence along with geological evidence to understand past environments
  6. Plant components that allow for good preservation
    • - cutin in leaf
    • - lignin in wood
    • - sporopollenin in spore and pollen walls
  7. Dendrites
    mineral patterns that look like fern fossils
  8. Compression-Impression fossils
    • - show external morphology (venation and outer form)
    • ...can sometimes show attachments of fruits, leaves, and branches
    • ...can show details of flower parts
    • - can preserve the cuticle also (waxy covering on leaf)
  9. Mold Casts
    show outer 3D form, but lack internal structures
  10. Permineralization
    shows internal cellular preservation
  11. Rock types
    • - Metamorphic: formed when heat and pressure alter other rocks into other forms (aka granite)
    • - Igneous: formed underground as magma, or above ground as lava from volcanic eruptions
    • ...ash falls from eruptions can preserve leaf compressions and silica from volcanoes can supersaturate the ground water to permineralize plant tissues
    • - Sedimentary: where you find fossils
    • ...grain size determines rock type: coarse<conglomerate<sandstone<siltstone
  12. Sedimentology
    interpret depositional environment based on patterns of rock distribution
  13. Depositional Environments
    places where plants grow prior to fossilization
  14. Allochthonous
    organic material transported and preserved away from the environment in which it grew originally
  15. Autochthonous
    organic material fossilized in the same place it grew
  16. Permineralization process
    lots of volcanic activity can produce massive amounts of silica that gets into the groundwater. The water that has totally soaked the plant tissues then becomes supersaturated or "permineralizes", catching the plant material and trapping it for us like a jello salad
  17. Coal
    coal is the carbon from fossilized plants. It can be studied by breaking down all the organic material and looking at what is left
  18. Amber
    amber is fossilized resin that can trap plant and insect material and preserve them
  19. Vegetative vs. Reproductive phases of life cycle
    • - Vegetative phase begins with germination, then continues to seedling, and then to mature plant; modular and indeterminate
    • - Reproductive phase begins with the flower from the mature plant and creates the seed that germinated to start the vegetative phase.
  20. Organs
    • Leaf: photosynthesis, sometimes for attraction or modifications
    • Stem: support, conduction storage, sometimes photosynthesis
    • Root: anchorage, conduction storage
    • Node: the point where the stem branches off to form a leaf
    • Internode: empty stem between the nodes
    • Indeterminate growth: growth that is not terminated, as opposed to growth that is terminated when a structure has been formed
    • Axillary bud: an embryonic shoot which lies at the junction at the stem and petiole of a plant
  21. Organography
    • - already established in the embryo
    • - Shoot apical meristem: stem tip
  22. Main features of stem, leaf, root; radial vs. bilateral symmetry
    • Stem: indeterminate, radially symmetric, phototrophic, nodes and internodes, derived from embryonic shoot apex or axillary buds
    • Leaf: bilaterally symmetric, determinate, produced at nodes, ephemeral
    • Root: indeterminate, radially symmetric, geotropic, lack nodes and internodes, produce a root cap

    • radial symmetry is like a starfish (or flower)
    • bilateral symmetry is like a butterfly
  23. Pith
    located in the center of the stem and roots, surrounded by xylem
  24. Cortex
    the outer layer of the stem or root bounded by epidermis on outside and endodermis on inside
  25. Vascular bundle
    • the xylem and phloem
    • xylem: transports water and some nutrients
    • phloem: carried nutrients
  26. Phyllotaxy
    leaves grow in a particular order
  27. Palisade and spongy mesophyll
    palisade mesophyll contains chloroplasts, spongy mesopyll allows passage of gases
  28. Midrib
    the center of the leaf containing the vascular tissue
  29. stomata
    pores found in the leaf and stem epidermis used for gas exchange
  30. Transition from vegetative to reproductive phase
    Changes from an indeterminate apical meristem to a determinate floral apex
  31. Flower and its parts
    • Stigma: composed of a filament that catches pollen
    • Style: structure through which the pollen tubes grow to get to the ovary
    • Ovary: encloses the ovules
    • Ovule: protective embryo covering; becomes the fruit
    • Pistil: the ovule producing part of a flower
    • Gynoecium: modified leaves or stems present on a gametophyte shoot; the innermost whorl of structures in a flower
    • Stamen: pollen bearing parts of the flower (the filament and the anther that sits on top of it, collectively)
    • Anther: contains pollen
    • Filament: the stalk that the anther sits on top of
    • Pollen: the sperm cells
    • Sepals: enclose and protect the flower when in bud form
    • Petals: attracts pollinators based on its bright color
    • Receptacle: where the parts of the flower attach to the stalk
  32. What happens when the ovule becomes the seed?
    The ovary and other structures becomes the fruit, and the embryo is in the seed
  33. Describe pollination after the pollen grain lands on the stigma
    pollen contains sperm, pollen tube develops and carried sperm to egg.

    • pollen is created with sperm via meiosis
    • embryo sac with egg is created via meiosis
Card Set
PLB 407
lectures 1 through 3