Much like guided missiles that sense the heat of a plane's engine, sperm are guided to the fertilization site by temperature, reports a Weizmann Institute study published in the current issue of ...

Mature ova are released from the ovary into the oviduct where they may be fertilised by sperm to form a zygote. In humans, fertilisation happens inside the woman’s body. This is a process called ...

"Chimeras are the result of fusion of two zygotes to form a single embryo, producing an individual with genetically different kinds of tissue. If the fused zygotes are of different sex, the individual ...