Some men produce too many sperms. That little-mentioned fact was the focus of my previous blog post. (See Why Too Many Sperms Spoil the Egg, posted on August 11, 2017.) With too many sperms, an ...

Human bodies have to be built from a single egg cell that's fertilized by a sperm cell. Many rounds of cell division occur as the body is developing, and it seems that there are plenty of chances for ...

Despite significant biomedical advances in recent decades, the very earliest events of human development¬--those that occur during a critical window just after fertilization--have remained an ...

Almost anyone with a high school education can correctly answer the question “When does human life begin?” by responding “at conception” or at “fertilization” of a human egg by a sperm cell. While we ...

A stunning explosion of zinc fireworks occurs when a human egg is activated by a sperm enzyme, and the size of these 'sparks' is a direct measure of the quality of the egg and its ability to develop ...

Christopher Arellano Reyes majored in biology and minored in chemistry and biotechnology and was a 2022-23 health care ethics intern with the Markkula Center for Applied Ethics at Santa Clara ...