If fertilization of ova and spermatozoa produces a diploid zygote, then what is fertilized to produce a diploid zygote?

Answer choices:
- graptolites
 - members of their own species
 - ova and spermatozoa
 - salt and pepper
 - mitosis
 - peachleaf willow
 - bacteria
 - light energy

 

   ova and spermatozoa       