The mutation rate to a lethal, recessive genetic illness is 10-10. Individuals die before they get a chance to reproduce. Under mutation-selection balance, what is the equilibrium frequency of the recessive allele? What is the equilibrium frequency of the genetic illness?
This is actually an easier question than it seems because some of the math collapses under the assumptions of mutation-selection balance with lethal recessive alleles.
I will take some background information from this website because it is explained so well http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=iga.section.3897:
"Another cause of genetic equilibrium in populations is the balance between the introduction of new alleles by repeated mutation and their removal by natural selection. This balance is probably the cause of many low-level polymorphisms for genetic diseases in human populations. New deleterious mutations are constantly arising spontaneously or as the result of the action of mutagens. These mutations may be completely ...
This job discusses the mutation rate and the selection rate.