In asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism.

In sexually reproducing organisms, one copy is normally inherited from each parent.

Almost certainly, the first sexually reproducing organisms produced only small motile gametes, as many simple animals and plants do today.

All sexually reproducing eukaryotic organisms derive from a common ancestor which was a single celled species.

In sexually reproducing organisms, speciation results from reproductive isolation followed by genealogical divergence.

Spermatozoa are the mature male gametes in many sexually reproducing organisms.

Cloning, any of various techniques used to reproduce genetically identical organisms from an individual organism; the organisms so produced are called clones.

The eggs of sexually reproducing organisms are adapted to avoid this situation.