Class 12th Biology 2018 Set1 Delhi Board Paper Solution
Explain the events upto double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
Fertilization process is the unique feature of the angiosperm life cycle. By the two sperms, one fertilizes with the egg for the formation of the zygote which is known as Syngamy; and the other sperm combines with the secondary nucleus which is known as the triple fusion to form the triploid nucleus (3n) that is calles primary endosperm nucleus in the large central cell of the embryo sac. And then the combination of two male gametes with the different nuclei of the embryo sac is known as double fertilization.
First, the fertilized egg becomes the zygote and then get developed into the embryo. After the division of primary endosperm nucleus, it gives endosperm. It is rich in nutrients so that it can take proper care of the developing embryo.
Double Fertilization:
And, as a result of the triple fusion, the primary endosperm nucleus is formed. It divides primarily to the zygote and forms the endosperm.
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