The graph of the relation between @DT07361@ and the proportion of individuals responding with an all-or-none effect; it is essentially the graph of the @P04855@ of an occurrence (or the proportion of a population exhibiting an effect) against @DT06810@. Typical examples of such all-or-none effects are mortality or the incidence of cancer. The @DT07361@-effect curve is the graph of the relation between @DT07361@ and the magnitude of the biological change produced measured in appropriate units. It applies to measurable changes giving a graded response to increasing doses of a @D01863@ or @XT06755@. It represents the effect on an individual animal or person, when biological variation is taken into account. An example is the increased effect of lead on the @H02714@ synthesis, e.g., on activity of the enzyme 6-amino laevulinic acid dehydratase in blood @ST06843@ or coproporphyrin levels in urine.