The above image shows sperm trying to get inside of an egg. When a sperm and an egg come together, it is called "fertilization."
What do you notice about the differences between the sperm and the egg? Which one is bigger? Which one is smaller? What does the shape of the sperm remind you of? How about the egg? Does it look like a chicken egg or something else? How are the male and female body systems so different from each other that one creates sperm and the other creates eggs? Think about these questions as you read about the male and female reproductive systems as well as how to keep the systems healthy.
Image copyright Sebastian Kaulitzki, 2014. www.shutterstock.com. Used under license from Shutterstock.com.