<p>It all depends on the graduate program and your major. Some will be relatively easy to accomodate as in your example. Other grad programs require a fairly huge amount of undergrad preparation, e.g. Classics (my field) where you need to have covered both Latin and Greek, at least one of them to a fairly advanced level, plus the obvious history, literature, and cultural surveys.</p>
<p>The websites of the various graduate departments will give you a good idea of what’s required for admission.</p>