Distinct molecules called agglutinogens (a type of antigen) are attached to the surface of red blood cells. There are two different types of agglutinogens, type A and type B. Each type has different properties.
MDB: Geodatabase. The geodatabase is a collection of geographic datasets of various types, with the most basic types being vector, raster, and tabular data. There are three types of geodatabases: file, personal, and ArcSDE. Geodatabases are the native data format for ESRI's ArcGIS.
ArcGIS implements topology through a set of rules that define how features may share a geographic space and a set of editing tools that work with features that share geometry in an integrated fashion.