Plants Sensory Systems and Hormones (yes, plants have hormones too!)

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Plants Sensory Systems and Hormones(yes, plants
have hormones too!)

• Ms. Bush
• Plants and Photosynthesis

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Outline for today

• Seedling development
• Plants and light
• Plant tropisms
• Plant hormones
• Quiz

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Double fertilization

• Grains of pollen fall on the stigma. The pollen
  grains grow down the style into the ovary.
• The pollen grains (microspores) meet up with the
  megaspores in the ovule. Microspores fertilize
  the megaspores.
• One microspore unites with an egg nucleus and
  eventually develops into a complete plant.
• The other microspore unites with two polar nuclei
  and develops into food for the plant, often in
  form a fruit.

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• Double fertilization a plant food

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Seedling Development
http//www.kidsgardening.com/onlinecourse/PartI5.h
tm
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Plants bloom based on the amount of uninterrupted
darkness
Freeman Biological Science 2 ed.
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Plant Tropisms

• Phototropism
• Gravitropsism
• Thigmotropism

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Phototropism
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Gravitropism
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Thigmotropism
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Plant Hormones
Functions of Plant Hormones Hormone Function Functions of Plant Hormones Hormone Function
Gibberellins Promotes stem elongation,
Cytokinins Promotes cell division and differentiation
Ethylene Induces leaf abscission and promotes fruit ripening
Abscisic acid Inhibits leaf abscission and promotes bud and seed dormancy
Auxins Promote plant growth and phototropism