A person who studies living organisms is called a biologist.

Here are some more specific terms depending on the type of living organisms they study:

* Zoologist: Studies animals

* Botanist: Studies plants

* Microbiologist: Studies microorganisms

* Ecologist: Studies the relationship between organisms and their environment

* Geneticist: Studies genes and heredity

* Physiologist: Studies the functions of living organisms

* Anatomist: Studies the structure of living organisms

* Paleontologist: Studies fossils of ancient life

* Taxonomist: Classifies and names organisms