Gymnosperms and introduction to the angiosperms

1
______________ ______
Section through a stamen
2
Microspores produced by ________
Four microspores
3
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Microgametophyte (Pollen) 2 cells
5
Generative cell divides by ______ to give rise to
the sperm
Sperm
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______
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Ovary and ovules
Micropyle
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Megaspore produced by ________Gametophyte
typically composed of 8 nuclei
Female gametophyte (_____________)
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MegagametophyteUsually eight nuclei and seven
cells
Egg
Synergids
______ nuclei
Antipodals
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Pollen tubes grow down the style and enters
_________
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Double fertilization in angiosperms
_____ nuclei
Egg
Tube nucleus
Sperm
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Double fertilization in angiosperms
Polar nuclei
One sperm fertilizes the egg The other
fertilizes the two _____ nuclei
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Egg Sperm -gt ZygotePolar nuclei Sperm -gt
_________
2 Polarsperm
Eggsperm nuclei
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Angiosperm vs. Gymnosperm Seeds

• Similarities
• Contain dormant embryo
• Seed coat from the testa
• Differences
• Main storage tissue ________ vs megagametophyte
• Naked or enclosed in a fruit

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Seeds vs. fruit

• Seeds fertilized ovules
• Fruit structures derived from _____ tissue

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The angiosperm life cycle differs from the pine
life cycle in that

• Pollen produce two sperm
• Sperm lack flagella
• Triploid endosperm is formed
• Two sperm cells fuse with the egg cell
• The megagametophyte contains the egg cell