noah took onto the ark:
Genesis 7: 2, where God tells Noah: 'Of every clean beast thou shalt take to thee by sevens, the male and his female: and of the beasts that are not clean by two, the male and his female'
so he either took 7 males and 7 females of the clean ones, or just seven in total, depending on how you understand the sentence. the idea of two by two is only relevant to unclean animals (like pigs, camels, eels, snails etc etc).
gotta love QI