Sexual reproduction in flowering plants (New syllabus chapter 1 / old syllabus Chapter 2)
Double Fertilization|reproduction in flowering plants|short notes| NCERT| standard 12| Biology
Find free test at the end of the article!
Note 11
This is the moment of fertilization in angiosperms.
Various step by step processes occur in this phase.
> In pollen-pistil interaction, various events occur, that would lead to
> Pollen tube makes it way through tissues of style and stigma.
> pollen grain passes 2 male gametes in pollen tube.
> revise notes of pollen-pistil interaction with the link below! ⬇️⬇️⬇️⬇️
https://www.gujaratbiologyneet.com/2023/08/note-10-standard-12sexual-reproduction.html
> Pollen tube first enters one of the synergids with help of filiform apparatus.
> Then pollen tube releases 2 male gametes into the cytoplasm of synergids
> here, double fertilization begins.
> 2 male gametes perform 2 types of fusion : 1) syngamy and 2) triple fusion
> 1) syngamy
>>> one of the two male gametes moves towards egg cell
>>> the male gamete fuses with the nucleus of egg cell.
>>> this fusion is called as syngamy.
>>> Syngamy produces a diploid cell - called as zygote.
>>> zygote further develops to into embryo
> 2) Triple fusion
>>> another male gamete moves towards centre of the cell - towards 2 polar nuclei
>>> fusion between 1 male gamete and 2 polar nuclei occur
>>> this fusion is called as triple fusion - because it involves fusion of 3 haploid nuclei
>>> triple fusion produces a triploid nucleus - Primary Endosperm Nucleus (PEN)
>>> In turn, central cell becomes Primary Endosperm Cell (PEC).
>>> PEC than develops into Endosperm.
 |
| Fertilised embryo sac showing zygote and Primary Endosperm Nucleus (PEN) |
If you want to make sure the concept of these notes are clear to you. Then give a try to the questions of this topic.
Click on the link given below to get free test.
⬇️⬇️⬇️⬇️⬇️
Double fertilization - free test
https://www.gujaratbiologyneet.com/2023/08/double-fertilization-free-test-11.html
If you have any doubts, please comment below.
Thank you for reading!
Keep learning!
Stay motivated!
Manish Mevada
Urvi Bhanushali
Please Do Not enter any sparm link in comment box