  We describe a simple meanfield variational approach to study a number of
properties of intrinsically stiff chains which are appropriate models for a
large class of biopolymers. We present the calculation of the distribution of
end-to-end distance and the elastic response of stiff chains under tension
using this approach. In the former example we find that the simple expression
almost quantitatively fits the results of computer simulation. For the case of
the stiff chain under tension we recover analytically all the known limits. We
obtain quantitative agreement with recent experiments on the stretching of DNA.
The limitations of our approach are also discussed.
