Angiosperm Reproduction and Biotechnology

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Angiosperm Reproduction and Biotechnology

• Chapter 38

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AngiospermsAnthophyta

• More specialized xylem evolved.
• Tracheids seen in gymnosperms gave rise to vessel
  elements
• Xylem is reinforced by second cell wall, the
  fiber (also seen in conifers)
• Flower is the reproductive structure
• Coevolution is seen between flowers and animals

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Sporophyte/Gametophytes

• The life cycle of the angiosperms shows very
  reduced gametophyte generations.
• What is the male gametophyte?
• What is the female gametophyte?
• What is pollination?
• Bringing pollen to the stigma.
• How does self-incompatibility work?
• Ability of a plant to reject its own pollen and
  sometimes the pollen of closely related
  individuals

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Double Fertilization

• The pollen tube grows following pollination and
  leads to double fertilization.
• What is fertilized?
• Sperm egg zygote (2n)
• Sperm 2 polar nuclei endosperm (3n)

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Seed Development

• Endosperm develops before embryo
• Endosperm provides food for developing embryo
• Embryo reaches a certain size and then enters
  dormancy until germination.

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Development of a eudicot embryo
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Germination

• How can seed dormancy be advantageous to a plant?
• Helps with dispersal
• Doesnt leave dormancy until conditions are good
• What are some conditions for breaking dormancy?
• Desert Only after good rainfall
• Chaparral fire
• Others coats weakened by digestive enzymes as
  they pass through animals digestive tract

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Germination depends upon.

• Imbibition-uptake of water due to the low water
  potential of the dry seed
• Hormone release

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• Radicle emerges from seed
• Shoot tip breaks through the soil.
• Until this point how has the embryo received
  nutrients?
• Endosperm(food)and radicle (water).

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The Fruit

• What is a fruit?
• After fertilization the ovary becomes the fruit.
  It protects the seeds.
• Name three modifications that different fruits
  have for seed dispersal.
• Sweeten and turns colorful when ripe
• Have burrs that can stick to animals fur
• Feathery like dandelions for wind dispersal of
  seeds

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Review the Evolution of Alternation of
Generations in Plants
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