Categories - Science
All of these categories are available in each of the 3 divisions. The 3 divisions are Elementary Division (5th Grade),  Junior Division (6th , 7th & 8th Grade) & Senior Division (9th, 10th, 11th, & 12th Grade).
Sub Categories
Taken from the Intel ISEF Category Descriptions

Animal Sciences

Behavioral & Social Sciences Biochemistry

Cellular and Molecular Biology

Chemistry Computer Science Earth Sciences Engineering: Materials and Bioengineering Engineering: Electrical and Mechanical Energy and Transportation Environmental Analysis Environmental Management Mathematics Medicine & Health Sciences Microbiology Physics and Astronomy Plant Sciences Team Projects