To compensate, many plants have evolved repair mechanisms and reproductive strategies that allow them to produce offspring even without the meeting of sperm and egg. (science.sciencemag.org)
The feat was long considered impossible in mammals because embryos were thought to need the different sets of genes that are switched on in sperm and eggs. (discovermagazine.com)
Those stem cells can then be turned into sperm and eggs. (theverge.com)