Science and Study:
* Biology: The study of living organisms
* Ecology: The study of the relationships between living organisms and their environment
* Geology: The study of the Earth's physical structure and history
* Psychology: The study of the mind and behavior
* Sociology: The study of human society
* Zoology: The study of animals
Other Fields:
* Astrology: The study of the influence of stars and planets on human affairs
* Ethnology: The study of different cultures
* Linguistics: The study of language
* Physiology: The study of the functions of living organisms
* Theology: The study of religion
* Mythology: The study of myths and legends
More Specific Examples:
* Archaeology: The study of past cultures through material remains
* Bacteriology: The study of bacteria
* Cardiology: The study of the heart
* Cryogenics: The study of very low temperatures
* Dendrology: The study of trees
* Entomology: The study of insects
* Herpetology: The study of reptiles and amphibians
* Ichthyology: The study of fish
* Meteorology: The study of weather
* Mycology: The study of fungi
* Neurology: The study of the nervous system
* Oncology: The study of cancer
* Paleontology: The study of fossils
* Pathology: The study of diseases
* Taxidermy: The art of preserving animal skins
* Virology: The study of viruses
This is not an exhaustive list, as there are many words ending with "-logy" in specialized fields and emerging areas of study.