Psychology 2040A/B Chapter 4: Chapter 4 - Textbook Notes

14 views22 pages

Document Summary

Prenatal development: development that occurs between the moment of conception and the beginning of the birth process. Development begins in the fallopian tube when a sperm penetrates the wall of an ovum, forming a zygote. From the moment of conception, it will take approximately 266 days for this zygote to become a fetus that is ready to be born. Prenatal development often divided into 3 major phases: phase 1 period of the zygote (germinal period): lasting from conception until the developing organism becomes firmly attached to the wall of the uterus. As the zygote moves down the fallopian tube toward the uterus, it divides by mitosis into 2 cells. These 2 cells and all the resulting cells continue to divide, forming a ball-shaped structure, or blastocyst, that will contain 60-80 cells within 4 days of conception. Inner layer of the blastocyst becomes the embryo. Outer layer of cells will develop into tissues that protect/nourish the embryo.