Achondroplasia is a disorder in which the bones do not grow to the normal size from the cartilage at the end of the limb bones.  In humans, this is can be caused by an autosomal dominant mutation. The result is abnormally short limbs, a condition called dwarfism.  But this isn’t a disorder unique to humans.  In some animals breeds, including dogs, horses, cats and chickens, this trait is selectively encouraged to produce dwarf versions of the original animal.  In this activity, you will take a look at how achondroplasia is passed in humans and how it is passed in other species as well.