Bio Text Final: 1

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  1. Seeds are prominent because of their __. 

    What are the advantages?
    great survival value

    •                                                                i.      Protection and stored food are available to the embryo even in critical stages of germination and establishment
    •                                                              ii.      It igives the seed a great selective advantage over their free-sporing relatives and ancestors over plants that shed their spores
  2. a.       All are __

                                                                   i.      Produce __ and __ that give rise to __ and __
                                                                 ii.      Seed producing is an extreme form of heterospory that has been modified to form an __(the structure that develops into the seed)
    1.       The seed is a __
    2.       An __ consists of a __, the structure in which megaspores are produced, surrounded by one or two additional layers of tissue, the __
    • heterosporous
    • megaspores and microspores
    • megagametophytes and microgametophytes
    • ovule 
    • matured ovule containing an embryo
    • immature ovule
    • megasporangium
    • integuments
  3. What led to the evolution of the ovule?
    • 1.       Retention of megaspores within the megasporangium (aka: nucellus)
    • 2.       Reduction in number of megaspore mother cells to one
    • 3.       Survival of one for the four megaspores
    • 4.       Formation of female gametophye inside the single functional megaspore—the formation of an endosporic female gametophyte that is no longer free living and is retained within the megasporangium
    • 5.       Development of the embryo, or young sporophyte, wthin the female gametophyte retained within the megasporangium
    • 6.       Formation of an integument that completely envelops the megasporangium, except for an opening at its apex called the micropyle
    • 7.       Modification of the apex of the megasporangium to receive microspores, or pollen grains
  4. Progression to development of Egg

    Explain Elkinsia.
    •                                                                i.      nucellus and 4-5 integumentary lobes with little to no fusion; they curved inward at their tips, forming a ring around the apex of the nucellus
    • 1.       Ovules were surrounded by dichotomously branched, sterile structures called cupules
  5. I.                    Components of a Seed: Embryo, Stored Food, and Seed coat
    a.       Ovule consists of a __
    b.      When ready for fertilization, the nucellus contains a __
    c.       After fertilization, the integuments become the __, and a seed is formed
    • nucellus enveloped by one or two integuments with a micropyle
    • megagametophyte composed of nutritive tissue and archegonia
    • seed coat
  6. I.                    Phyla of Seed Plants
    a.       Seed-bearing plants called__
    b.      All seed plants have __, which are large leaves with several veins, but are modified to needles or scales in some groups
    c.       Phyla?
    • seed ferns
    • megaphylls
    • i. Confers ii. Cycads iii. Gingki iv. Gnetophyes v. Anthophyta
  7. I.                    Seed Ferns
    a.       Remains of seed ferns are common fossils in rocks of Carboniferous age
                                                                   i.      __ were so fernlike that these plants were long regarded as ferns
    1.       __: Oliver and Scott discovered they had seedsà gymnosperms
    • Large, pinnately compound fronds
    • 1905
  8. Structure of seed ferns

    Living or  not?
    tall, woody trees

    Fronds: borne at the top of the stem, or trunk and the fronds had microsporangia and seeds

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Bio Text Final: 1
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