Do mutations occur because the organism needs a new trait ?

What is the inability of an individual or a society to achieve a minimum standard of living known as ?

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

This group of organisms perform the process of ammonifcation. a. herbivores b. decomposers c. carnivores c. plants