Fact 1: Fertilization occurs when a sperm and an egg fuse.

Fact 2: Fertilization is the penetration of the egg by a sperm.

Given the two facts above, answer the question "What do sperm penetrate?" with the following options: 
- pollen
 - eggs
 - seeds
 - cells
 - plants
 - chromosomes
 - mines
 - skin


 

  eggs       