Before revision: Eukaryotic cells can detect the direction of a chemoattractant gradient precisely by generating intracellular gradients of signaling molecules that mirror the extracellular gradient ? an ability called directional sensing.
After revision: Eukaryotic cells can detect the direction of a chemoattractant gradient precisely by generating intracellular gradients of signaling molecules that reflect the extracellular chemical gradient - an ability called directional sensing.