Answer:
O H20 and CH4, but not O2
Explanation:
Compounds consist of multiple elements. O2 is just two oxygen atoms, meaning two atoms from the same element.
The subject area of Chemistry is a very broad area. So, it is classified into sub-branches like inorganic chemistry, organic chemistry, physical chemistry, quantitative chemistry and many more. But when the basis is on the composition of elements, it is divided into inorganic and organic chemistry. Compounds containing the element Carbon are all under organic chemistry. If they do not contain carbon, they are considered as inorganic.
During the early times, the only differentiation between these two sub branches is the vital theory. This theory proposes that all things that have life can be only made by nature alone are inorganic. But thing was disproved by Wohler when he was able to synthesize urea from inorganic compounds. Thus, today the only differentiation is the carbon atom.
It is very easy and simple difference that is antigens and antibodies .
it can be different due to donor and recipient also .
A type blood having antigens
whereas B type blood having nil.
B type blood having antibodies
whereas A type blood having nil.
Due to divergent evolution, some species may have similar anatomical structures with the same purposes. The species while not exactly similar are close enough to allow the interbreeding of the two, such as the horse and mule