Water.
Sound travels slowly because the amount of pressure.
DNA polymerase is an enzyme with a specific active site complementary to the 3' OH end of the DNA strand in terms of charge, size, orientation and shape thus can only bind to 3' end and cannot bind to 5' end for replication to occur
It is sub-classified as a rough, or granular ER, and a smooth or agranular ER. The rough Endoplasmic reticulum is lined with ribosomes and modifies and packages proteins that have been produced by the ribosome. In skeletal and cardiac muscle it is known as the sarcoplasmic reticulum.