Describe an example of how maintaining biodiversity has a direct economic value for humans

Which animal group is the largest and contains more species from all the other living groups combined? is it mammals or

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere

What is the one part of the nucleotide  that differs among the other different nucle  tides?