In a sample of cancer cells, a specific gene has become duplicated many times. Is this gene likely to be an oncogene or a tumor-suppressor gene? Explain your reasoning.

Solution Strategy

What information is required in your answer to the problem?

Whether the gene is likely to be an oncogene or a tumor-suppressor gene, and why.

What information is provided to solve the problem?

For help with this problem, review:

Oncogenes and Tumor-Suppressor Genes in Section 16.2.

Solution Steps

The gene is likely to be an oncogene. Oncogenes stimulate cell proliferation and act in a dominant manner. Therefore, extra copies of an oncogene will result in cell proliferation and cancer. Tumor-suppressor genes, on the other hand, suppress cell proliferation and act in a recessive manner; a single copy of a tumor-suppressor gene is sufficient to prevent cell proliferation. Therefore, extra copies of the tumor-suppressor gene will not lead to cancer.