Hybridization: This is when two animals from distinct species mate to produce a hybrid, like the mule. It's like mixing two different colors of paint to create a new color.
Sterility: Most mules can't reproduce because they have an odd number of chromosomes. This is similar to trying to pair up socks when you have one extra - there's always one left without a match, which prevents normal meiosis (cell division).
Donkey: A donkey is a domesticated member of the horse family. They're smaller than horses and known for their endurance and tough nature. Think of them as the off-road vehicles of the equine world.