"gain of function" mutations are generally dominant because one copy in a diploid organism is sufficient to alter the normal phenotype. truefalse

True

Explanation:

"Gain of function" mutations are mutations that alter the gene product.. This means that the gene gets a new molecular function or a new pattern of gene expression. The random change leads to new function on the gene.

The change is expresses in a heterozygote, which means that the gain-of-function mutation most likely will act like a dominant allele.

that is wrong, its not thymus.