Photosynthesis is the primary mover of nitrogen, true or false?

Food webs - transferring energy and matter from one level to another. here you see four food webs. one or more are incorrect. which food web(s) show the correct sequence of organisms, from start to top level consumer? a) a b) d c) c d) a and d

Which of these is not a nucleotide base found in dna?

Up to what percentage of the world's flora consisted of cycads during the triassic period? 100% 75% 50% 20%