Final answer:
Oncogenes are dominant alleles with gain-of-function mutations. An example is the Myc gene, which is aberrantly activated in Burkitt's Lymphoma.
Step-by-step explanation:
Oncogenes are dominant alleles that contain gain-of-function mutations, which means that the actions of the mutant allele gene product, often resulting in a constitutively activated protein, are dominant over the gene product produced by the normal allele. An example of an oncogene is the Myc gene, which is aberrantly activated in Burkitt's Lymphoma. Overexpression of Myc transforms normal B cells into cancerous cells that continue to grow uncontrollably.