We generalize work of Lascoux and Jo zeeak-Pragacz-Weyman on Betti numbers for minimal free resolutions of ideals generated by 2 2 minors of generic matrices and generic symmetric matrices, respectively. Quotients of polynomial rings by these ideals are the classical Segre and quadratic Veronese subalgebras, and we compute the analogous Betti numbers for some natural modules over these Segre an...