What is the difference between proto-oncogenes and tumor suppressor genes? what is the difference between proto-oncogenes and tumor suppressor genes? proto-oncogenes are modified via mutation to stimulate normal cell growth and division and tumor suppressor genes allow uncontrolled growth proto-oncogenes are modified via mutation to allow uncontrolled growth and tumor suppressor genes stimulate normal cell growth and division proto-oncogenes prevent uncontrolled growth and tumor suppressor genes stimulate normal cell growth and division proto-oncogenes stimulate normal cell growth and division and tumor suppressor genes prevent uncontrolled growth

Proto-oncogenes stimulate normal cell growth and division and tumor suppressor genes prevent uncontrolled growth

Explanation:

Both gene types play a role in cancer development.

Proto-oncogenes are genes responsible for the control of normal cell growth. They encode for proteins that induce growth and proliferation of the cell. When mutation occurs, proto-oncogenes become oncogenes and contribute to the development of cancer. As a consequence, the cell cannot control its growth.

On the other hand, tumor supressor genes normally have repressive effect on the cell growth (promote cell death-apoptosis). When a mutation in this gene occurs, this gene loses its function an that also leads to uncontrolled cell proliferation.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.