Final answer:
Glycophorin A is a dimer with oligosaccharide chains that bear negative charges to prevent red blood cells from clumping together.
Step-by-step explanation:
Glycophorin A is a dimer with 16 oligosaccharide chains bearing negative charges that may prevent red cells from agglutinating or clumping together.
The negative charges on the oligosaccharide chains repel each other, creating a barrier between the red blood cells and preventing them from sticking together. This is important for maintaining the flow of blood and preventing blockages in the blood vessels.