An apiologist.
a beekeeper
They study diseases.
Biologists.
a geneticist
Neurologists study the nervous system.
It depends on what kind of scientist it is. For example, botanists study plants.
a physist
A herpetologist studies lizzards and snakes.
Computer Science and IT (Information Technology)
Zoologists study animals.
All scientist study science so every one you could think of :)
bio