You are presented with the question "Fertilization occurs when an egg and what join together to form a diploid zygote?" and the following answer choices: 
- rapid expansion
 - testosterone
 - gastropod shells
 - penis
 - peachleaf willow
 - pollen
 - male hormone
 - male gamete

Now knowing that fertilization occurs when a sperm and an egg fuse to form a diploid zygote and male gametes are called sperm, choose the best answer.


 

        male gamete 