Gosh. I hope none. These are some of the 'objective' ways that graduate schools determine that an applicant can endure and sustain throughout graduate studies. Quite frankly, graduate school counselors often recommend 1) retaking GREs to improve scores (although I believe lower scores are still reported, but highest scores are taken into consideration), and 2) sometimes earning an Master's degree to compensate for low UG GPAs. The latter is time-consuming, costly, and often doctoral programs may transfer no more than 6 masters-level credits as you earn an additional Master's along the way, but it's important to note that these programs are so competitive because your fellow applicants usually have high GPAs and strong GRE scores...so you do what you have to do to make yourself the most competitive that you can be (...like the Army's old slogan "Be all that you can be."), and see were chips may fall (b/c there's some luck in this process, too).