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

The process of embryogenesis is very complex, with continuous cell division and differentiation.

He is an expert in seismology.

A large earthquake occurred yesterday, throwing the entire town into chaos.

A large earthquake occurred yesterday, throwing the entire town into chaos.

The seismologist is studying earthquake prediction and disaster prevention.

He is an expert in seismology.

We camped in a densely wooded area.

He is writing a thesis on abiogenesis.

I am majoring in developmental biology at university.