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Q.
The endosperm in angiosperms is
COMEDKCOMEDK 2014Sexual Reproduction in Flowering Plants
Solution:
In angiosperms, double fertilization which is a unique angiosperm feature (first discovered by Nawaschin in $1898$ in Fritillaria and Lilium) occurs when one male gamete fuses with the egg cell to produce diploid zygote while the other male gamete fuses with diploid secondary nucleus (formed by fusion of two polar nuclei) to produce primary endosperm nuclei which produces endosperm. As endosperm results by fusion of a diploid nucleus and a haploid gamete hence it is a triploid structure.