Lipids and proteins can be formed from carbohydrates. Which elements do these molecules have in common that help form different molecules?

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

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

What advantages does a pedigree have over a written passage?