You are presented with the quiz "what are united in fertilization for form a diploid zygote?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "gametes then unite in fertilization and form a diploid zygote" and "examples of gametes are ova and spermatozoa". 

So, what's the best answer to the question?


 

      ova and spermatozoa     