Geomorphology is the science that studies the surface shape of the earth.

He is majoring in geology.

He is an expert in pathology.

He is an expert in immunology.

He is an expert in ichthyology and has a deep knowledge of marine life.

He is an expert in anthropology.

He is an expert in virology.

He has a deep interest in teratology.

I am majoring in embryology at university.

He is an expert in embryology, studying the developmental processes of many kinds of organisms.