10. A geneticist introduces a transgene into human cells and isolates five independent cell lines in which the transgene hasintegrated into the human genome. In four of the lines, the transgene is expressed strongly, but in the fifth there is noexpression at all. Which is a likely explanation for the lack of transgene expression in the fifth cell line?
(A) The transgene was mutated during the process of integration into the host cell genome.
(B) A transgene integrated into a euchromatic region of the genome.
(C) A transgene integrated into a heterochromatic region of the genome.
(D) The host cell lacks the enzymes necessary to express the transgene.
(E) A transgene integrated into a region of the genome characterized by high histone acetylation.