According to the "List of biology disciplines" topic they are: Anatomy, Astrobiology, Biochemistry, Bioinformatics, Botany, Cell biology, Ecology, Developmental biology, Evolutionary biology, Genetics, Genomics, Marine biology, Human biology, Microbiology, Molecular biology, Origin of life, Paleontology, Parasitology, Pathology, Physiology, Taxonomy, Zoology
Sorry, I only know of two: Botany and Zoology. Botany is the study of plants while Zoology is the study of animals. Where the other 23 got to I have no idea :(