the fusion of a sperm and an egg cell to produce a zygote. External occurs outside the female's body, as in fish and amphibians. Mammals, birds and reptiles have internal fertilisation.

FERTILIZATION: "Fertilisation in humans happens in the fallopian tubes."
Cite this page: N., Pam M.S., "FERTILIZATION," in PsychologyDictionary.org, May 11, 2013, https://psychologydictionary.org/fertilization/ (accessed August 8, 2020).