Water provides the needed for the first part of photosynthesis a) oxygen b)electrons c)carbon dioxide d) glucose

Radiometric dating is used to tell the absolute age of materials by studying the decay rate of radioactive isotopes. the decay rates of isotopes are constant and are expressed as .

Why is the theory of evolution important? it disproves all other theories about how life began. it provides a topic for debate. it is a unifying concept in biology. it explains how life began. i know for sure, it is not "it is a unifying concept in biology."

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above