Which choice is a chemical messenger that can directly influence gene expression? a. nonsteroid hormone b. steroid hormone c. atp d. camp

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.

answer; hydrologic cycle;