on the head of a bald person, will one be able to see the sulcus or gyrus clearly? why/Why not?

Dear student, 

Even though the person is bald, It is not possible to see the sulcus or gyrus.
Sulcus is a groove or depression in our cerebral cortex, which surrounds the gyrus and gives the brain a folding appearance. Since sulcus or gyrus is too deep therefore,  it is not visible from outside.

Regards.