Not all of the members of everyday categories have the same. Most fish have gills, fins, and scales. Sharks lack the feature of scales, yet they are still categorized as fish. This is most problematic for the approach to categorization.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.

a) carbon, hydrogen

b) carbon, hydrogen, oxygen, nitrogen

c) carbon, hydrogen, oxygen, nitrogen, phosphorus

d) sugar

e) amino acid

f) nucleotide