Final answer:
Polyspermy results in a nonfunctional zygote due to the formation of a triploid organism with an excess of chromosome sets, leading to defects and early embryonic death.
Step-by-step explanation:
Polyspermy results in a nonfunctional zygote. When more than one sperm fertilizes an oocyte, it leads to the formation of a zygote with an excess number of chromosome sets, specifically a triploid organism, which is not viable for life. Additionally, this situation can lead to defects such as neural tube defects in the developing fetus, and ultimately the inevitability of the embryo, leading to its death within a few days post-fertilization. Normally, once a sperm fuses with an oocyte, the oocyte enacts mechanisms to prevent other sperms from penetrating, as part of the slow block to polyspermy, such as forming an impenetrable fertilization membrane around the nascent zygote. Nevertheless, these mechanisms are crucial as polyspermy disrupts normal development, preventing the organism from reaching maturity.