Answer:
ecosystem
Explanation:
not population, not an organism, not a community
The SDS detergent solubilizes the phospholipids and proteins
I think it is the first one (or the last one, i am not sure I understand the statements), but the point is that all species have the same gene code for the same proteins and amino acides, for example the aminoacid Cytosine is encoded the same in all species
I believe it's the body area examination, since a 'back' isn't and organ
Hope this helpss