Analysis of early human embryos reveals that DNA duplication after fertilization is highly inefficient. This causes DNA damage, chromosome breaks and abnormal numbers of chromosomes, impairing embryo ...

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 ...

Who hasn't seen it before: the view through the microscope in which a sperm penetrates an egg cell and fertilizes it. This fundamental step in procreation happens dynamically and seemingly without ...

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 ...