Help me on this please

What is the amount of organic matter in all living organisms in a habitat called?

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted

In what type of geographic location did humans tend to develop civilizations?