Scientists worked out the structure of DNA in the 1950s ... 46 chromosomes in total. Human sex cells or gametes (egg and sperm) only contain 23 chromosomes in total. Each chromosome contains ...

The middle piece is packed with mitochondria to release energy needed to swim and fertilise the egg. The tail enables the sperm to swim. The nerve cell is extended, so that nerves can run to and ...

The chromosomes of sperm cells are tightly packaged ... across the zona pellucida surrounding the egg. It may also be that the nucleoprotamine structure protects the genetic material in the ...

Results were published Thursday in the journal Cell. Scientists had previously known about two proteins, one on the surface ...

Primordial germ cells, the founder cells of the germ line, are set aside in the early animal embryo, and divide and differentiate to produce sperm and egg ... of chromatin structure and the ...