It really depends on the school. A good number of universities today use computers to filter out potential applicants with credentials that are below their set minimums. This may prevent the admission committee from seeing ANY of your other credentials if your application was, from the filtering process, sent directly to the list of apps they won't even consider.
However, you'll never know whether the school(s) you're applying to do this or not. And if they DO, it's difficult to say WHICH credentials they will use in their filter or what the exact minimums will be. Though, I would suspect undergrad GPA and GRE subject test scores would be the most likely stats used in such a process. And of course most schools, if they have room left over for more admits, will begin considering those previously weeded out by their filtering system.
That said, it's still worth applying to ALL the schools you wish to attend because you can never be sure of each school's exact admission procedure. And it would be a shame not to apply to a favorable school because you didn't THINK you would have been admitted, but were wrong. Yes, the application fee is annoying, but it's a small price to pay for the chance of getting into your dream school(s). ^_^
And of course, always have back-ups. -__-