* Sperm need not be [[Copulation_-Sperm_in_the_Female_Tract_-_Anatomy_%26_Physiology#Capacitation|capacitated]], they can be epididymal.
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* Sperm need not be [[Copulation_-Sperm_in_the_Female_Tract_-_Anatomy_%26_Physiology#Capacitation|capacitated]], they can be epididymal,testicular or even a spermatid.
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** Only requirement is genes and cytoplasm
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** Even dead freeze-dried sperm have been effective in mice.
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* Abnormalities are frequent.
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* Power is in the hands of the operator, as it bypasses the process of selection in the female tract.