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?

The correct answer is - dominant-negative mutant allele.

Explanation:

The dominant-negative mutation is present in the case given in the question. Dominant-negative mutation acts opposite to the wild - type allele by altering the product of a gene such as the amount of the enzyme activity in cells.

In WT or wild type the enzyme activity is 200 units where it is homozygous for mutant and heterozygous the enzyme activity is zero which establishes that the mutant allele is dominant and has a negative effect on it.

Thus, the correct answer is - dominant-negative mutant allele.