The amount of enzyme activity in a cell that is homozygous for a mutant allele is 0 units. The amount of enzyme activity in a cell homozygous for the WT allele is 200 units. The amount of enzyme activity in a heterozygote is 0 units. What type of allele is the mutant allele?
◦ null/ amorphic
◦ hypomorphic
◦ hypermorphic
◦ dominant negative
◦ neomorphic