The earth consists of a variety of different organisms. despite their diversity, however, some similarities on the structural and metabolic levels may be seen. these similarities can be attributed to

It seems that you have missed the essential options to answer this question, but anyway, here is the answer. The Earth consists of a variety of different organisms. Despite their diversity, however, some similarities on the structural and metabolic levels may be seen. These similarities can be attributed to similarities among organisms in their proteins and nucleic acids. Hope this answer helps.

It doesn’t show the symbol

They must use the scientific method