An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?

An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in CELL TO CELL RECOGNITION.
Carbohydrates have diverse functions, one of their functions is that they serve as a recognition signal at the surface of cells.
Carbohydrates located on the surface of cells enable cells to recognize and  communicate with one another.

Because they are stupid and insensitive