On the outer surface of the plasma membrane there are marker molecules that identfy the cell-type?

Question

often these molecules are
A) amino acids
B) nucleotides
C) oligosaccharides
D) inorganic ions

Answer 1

C) oligosaccharides

Answer 2

(A) amino acids (or membrane proteins, to be exact)

Example: e-cadherin and cytokeratins indicate epithelial cells, while vimentin indicates a mesenchymal cell.