Describe the journey of the sperm and egg from ejaculation and ovulation to conception, and then ...

Sample response:
The egg that was released from the ovary is drawn up into the fallopian tube. One sperm cell from the ejaculate must meet and penetrate the egg. Once conception has taken place, this new organism is called a zygote. Over the course of two to four days, it divides and moves down the fallopian tube to the uterus. By the time it arrives in the uterus, it consists of about 90 cells. It is now called a blastocyst. On the sixth or seventh day after fertilization, it implants in the wall of the uterus. The successful attachment is the beginning of pregnancy. Once implantation occurs, the blastocyst is referred to as an embryo.