Answer
Gyrus – thick fold on the cerebral surface of the brain.
Sulcus – shallow grooves on the cerebral surface of the brain.
Work Step by Step
Gyrus comes from gy- meaning “twist, turn”. Gyri are the thick folds on the surface of the brain.
Sulcus comes from sulc- meaning “ furrow, groove”. Sulci are the shallow grooves on the surface of the brain.