Ordinarily, in the process of double fertilization, the pollen tube enters the synergid and releases two sperm. One of these will join with the egg cell to form the zygote, which develops into the embryo and associated scutellum. The other sperm joins with the polar nuclei to form the triploid primary endosperm nucleus, which develops into the endosperm. This results in a concordance of genotype between the embryo and endosperm; this allows many characters expressed in the endosperm to be scored without growth of the F1. For this reason, the persistent endosperm provides a major advantage to maize as a genetic organism—it eliminates a generation time of growth in many analyses and allows manipulation and foresight before planting.