generative nucleus

plant anatomy

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June 29, 2026

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In plant anatomy, the generative nucleus is one of two nuclei formed from the first division of a pollen grain's nucleus in seed plants. This nucleus is crucial because it gives rise to the sperm nuclei, which are essential for fertilization.1

The process begins with a microspore developing into a male gametophyte, also known as a pollen grain. Within the pollen grain, the nucleus divides. One resulting nucleus is the tube nucleus, which guides the growth of the pollen tube. The other is the generative nucleus. This generative nucleus then divides again to form two sperm nuclei. These sperm nuclei are vital for the double fertilization process unique to flowering plants, where one sperm fertilizes the egg to form an embryo, and the other fuses with polar nuclei to create the endosperm, a nutrient-rich tissue for the developing seed.234

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plant reproductive system
Angiosperms
…involves formation of a small generative cell and a tube cell. The generative cell may divide to form two sperm cells before the pollen grain (developing male gametophyte) is shed or while the pollen tube is growing during germination. The pollen grains of angiosperms have variously, and often elaborately, ornamented…
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…involves formation of a small generative cell and a tube cell. The generative cell may divide to form two sperm cells before the pollen grain (developing male gametophyte) is shed or while the pollen tube is growing during germination. The pollen grains of angiosperms have variously, and often elaborately, ornamented…
Read More

seed
Angiosperm seeds
The other two, the generative nuclei, can be thought of as nonmotile sperm cells. After reaching an ovule and breaking out of the pollen tube tip, one generative nucleus unites with the egg cell to form a diploid zygote (i.e., a fertilized egg with two complete sets of chromosomes,…
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The other two, the generative nuclei, can be thought of as nonmotile sperm cells. After reaching an ovule and breaking out of the pollen tube tip, one generative nucleus unites with the egg cell to form a diploid zygote (i.e., a fertilized egg with two complete sets of chromosomes,…
Read More