fertilisation in flowering plants

1
Reproduction in flowering plants
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OBJECTIVE

• Describe the process of fertilization in
  flowering plants

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Embryo sac
Name the parts
4
fertilization in flowering plants

• Pollen grains land, stick to the stigma and
  germinates to form pollen tube, which grows
  through the tissue of the style towards the
  ovary.
• The pollen tube gets into the embryo sac through
  the micropyle
• The tip of pollen tube nucleus disintegrates,
  creating a passage for the male nuclei.

5
Cont.

• The generative nucleus undergoes mitosis, forming
  two male nuclei.
• The egg cell fuses with the male nucleus to form
  a diploid zygote. The zygote undergoes mitosis to
  form an embryo.
• The two polar nuclei fuse with the second male
  nucleus to form a triploid nucleus.
• The triploid nucleus forms the endosperm. The two
  con current fertilization incidents are
  collectively referred to as double fertilization

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Embryo sac
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Events following fertilization....
Part Develops into
Zygote embryo
Endosperm nucleus endosperm tissue.  
Petals, stigma, style and stamens wither and fall off  
Ovary fruit
Ovary wall pericarp
Ovules seeds
Intergument testa
8
What is double fertilization?

• takes place in flowering plants when one male
  nucleus fuses with egg nucleus to form a diploid
  zygote while the other male nucleus fuses with
  polar nuclei to form a triploid endospermic
  nucleus