2. In the Australian Shepherd, Hereditary Cataracts is an autosomal dominant disorder that results in abnormal clouding of the lenses of the eye. In some Aussies, heterozygous for Hereditary Cataracts, the disease is not always expressed. Based on this information, answer the following questions:

a. Provide the terminology that best describes why some Aussies express Hereditary Cataracts and some Aussies do not express the disorder.
b. Several alleles are responsible for Hereditary Cataract formation. When present, some alleles result in very rapid cataract growth, whereas; other alleles result in very slow cataract growth. What terminology best describes the behavior of these various alleles?