11. The experiment was terminated before the sperm made it into the egg cell . 12. Egg cells travel through the oviduct to the fertilization chamber, where fertilization occur.13. In developing the human clone, the researchers started with a donated female egg cell . 14. It happens when the oocytes, or egg cells , in her ovaries are used up. 15. The altered egg cells , called oocytes, are chemically manipulated to make them start dividing. 16. Sperm and egg cells similarly only share some of the chromosomes of the parent. 17. Recently, other scientists reported that they had turned mouse stem cells into egg cells . 18. Fertilization is the event where the egg cell fuses with the male gamete, spermatozoon. 19. Each egg cell possesses a random selection of genes from its mother or father. 20. Each of them contains a single oocyte ( immature ovum or egg cell ).
