What is the point at which the sun crosses the equator to make night and day the same length during the second time of the year?

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?

In a cladogram' when does a group of organisms branch off

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