Bacteria produce many restriction endonucleases. What prevents these enzymes from degrading the host dna?(choose from the list of options)
1.a bacterium will produce endonucleases that recognize sequences that are not present in its own dna
2.the strong association between the histones and bacterial dna prevent the endonucleases from acting on them
3.the endonucleases are transpoted out of the cell so quickly they cannot significantly affect the host dna
4.the host dna is specially methylated and is therefore protected from cleavage