Aflea feeds off the blood of a dog. the flea is able to obtain nutrients from the blood, but the dog can become anemic. what type of relationship is this? a. commensalism b. predator-prey c. mutualism d. parasitism

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures