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Unit 1:
Ch. 1
Ch. 2
Ch. 3
Interlude A
Unit 2:
Ch. 4
Ch. 5
Ch. 6
Ch. 7
Ch. 8
Ch. 9
Interlude B
Unit 3:
Ch. 10
Ch. 11
Ch. 12
Ch. 13
Ch. 14
Ch. 15
Interlude C
Unit 4:
Ch. 16
Ch. 17
Ch. 18
Ch. 19
Interlude D
Unit 5:
Ch. 20
Ch. 21
Ch. 22
Ch. 23
Ch. 24
Ch. 25
Ch. 26
Ch. 27
Ch. 28
Ch. 29
Ch. 30
Interlude E
Unit 6:
Ch. 31
Ch. 32
Interlude F
Unit 7:
Ch. 33
Ch. 34
Ch. 35
Ch. 36
Ch. 37
Ch. 38
Interlude G

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At Long Last, Scientists Figure Out How Plants Grow
Nature, 26 May 2005

It has long been one of the great mysteries in plant science. Since 1885, scientists have known of the existence of the plant growth hormone auxin. And they've known of its dramatic effects on plant growth and development since the 1930s. But only now do scientists know how it works.

» Read the full article

Active Reading Questions

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    According to your book, auxin has which of the following effects on plant growth?
    a) Auxin influences apical dominance.
    b) Auxin controls how plants bend toward sunlight.
    c) Auxin promotes root formation.
    d) All of the above.
  2. fiogf49gjkf0d
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    Auxin is a plant hormone; its actions are slow and dependent on ratios of auxin to other hormones. If a plant’s apical tip is cut off, the plant begins to branch and get bushy. Which of the following is the best explanation for this?
    a) The apical tip is most likely where auxin is produced.
    b) Auxin levels in the plant drop when the apical tip is removed.
    c) Another hormone stimulates lateral branches to form and the plant to get bushy.
    d) All of the above.
  3. fiogf49gjkf0d
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    If scientists knew how auxin worked for so many years, why is the elucidation of the exact pathway of how it works so important?
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