  We have studied the separation of a double stranded DNA (dsDNA), which is
driven either by the temperature or force. By monitoring the probability of
opening of entire base pairs along the chain, we show that the opening of a
dsDNA depends not only on the sequence but also on the constraints on the chain
in the experimental setups. Our results clearly demonstrate that the force
induced melting of dsDNA, whose one of the ends is constrained, is
significantly different from the thermal melting, when both ends free.
