Like Fizzcube said That Rumour is a lie
Sometimes moves like Attract work on Pokemon with opposite genders
Same goes with abilitys like Rivalry work on Pokemon with the same gender.
With Egg Breeding The female species makes the eggs always the Pre-Evolution of the females
Sometimes the Pokemon may have Different Forms for the Female/Male E.g Frillish,Jellicent
Some Pokemon have Male/Female counterparts e.g Volbeat and Illumise
Hope this is the Answer your looking For