80 which gene expression is blocked in the lac operon system? (if wrong, answer will be reported). 1. the repressor protein destroys the genes required to produce enzymes. 2. lactose binds to the repressor and changes its shape. 3. the repressor protein blocks the genes from making mrna 4. rna polymerase begins transcribing the genes.

Subduction zones form when an oceanic plate collides with another oceanic plate or continental plate. the continental crust is lighter and less dense than oceanic crust. continental crust's density is approximately 2.7 grams per cubic centimeter. oceanic crust is thinner and the average density is about 3.3 cubic centimeters. when the two crustal plates converge the oceanic plate always bends and subducts beneath a continental plate. once the oceanic crust subjects, the rocks are subjected to changes in heat and pressure. because of this, we would expect to find rocks in the area of a subduction. a) clastic b) igneous c) metamorphic d) sedimentary