Which explains a difference between prokaryotic and eukaryotic gene reguation? A. Eukaryotic gene regulation is controlled by more than one promoter and one regulator. B. Prokaryotes do not have mRNA, so they do not have processes to degrade mRNA. C. Eukaryotes utilize operons, so they do not need to produce sections of mRNA. D. Prokaryotes process DNA in the nucleus, so genes do not need to be activated.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.