Zabi halaye biyu na hadi na waje?
Amsar ita ce: Ana jefa kwayoyin halittar jima'i (gametes na maza da mata) a cikin ruwa.
Ana daukar hadi a waje a matsayin nau'in hadi, yana faruwa ne lokacin da kwayoyin halittar maza da mata ke haduwa a wajen jikin mace, kuma yana kara samun damar haihuwa da girma. Hadi na waje yana da alaƙa da yiwuwar ƙirƙirar miliyoyin ƙwai da maniyyi, wanda ke ƙara damar samun ciki da samuwar embryo cikin sauri da sauƙi. Hakanan ana siffanta ta da hadi da ba a saba ba, saboda hadi na iya faruwa a wurare daban-daban. Bugu da kari, hadi a waje yana da siffofi da yawa, wadanda suka hada da: samuwar gates (namiji da mace) a wajen jikin mace, da kuma hadewar mazaje da nama a wajen jikin mace, hadi da waje yana da fa'idodi masu yawa, kuma ana la'akari da shi. daya daga cikin manyan hanyoyin haifuwa a cikin halittu masu yawa.Rayuwa, kuma yana daya daga cikin hanyoyin da suka fi dacewa wajen ci gaban amfrayo.
