After fertilization the outer integument forms
Testa
Tegmen
Perisperm
Pericarp
$A$ : Triple fusion is associated with the sexual reproduction in all spermatophytes.
$R$ : It is required to form definitive nucleus as nutritive tissue.
Definitions / Explanation : Double Fertilisation
What is meant by double fertilization? Explain.
Syngamy and triple fusion is called ... $A$... The central cell becomes ...$B$... develops into ...$C$... and zygote develops into ...$D$...
$A, B, C, D$ in the above statement are