  We investigate the effects of Quantum Gravity on the Planck era of the
universe. In particular, using different versions of the Generalized
Uncertainty Principle and under specific conditions we find that the main
Planck quantities such as the Planck time, length, mass and energy become
larger by a factor of order 10-10^{4} compared to those quantities which result
from the Heisenberg Uncertainty Principle. However, we prove that the
dimensionless entropy enclosed in the cosmological horizon at the Planck time
remains unchanged. These results, though preliminary, indicate that we should
anticipate modifications in the set-up of cosmology since changes in the Planck
era will be inherited even to the late universe through the framework of
Quantum Gravity (or Quantum Field Theory) which utilizes the Planck scale as a
fundamental one. More importantly, these corrections will not affect the
entropic content of the universe at the Planck time which is a crucial element
for one of the basic principles of Quantum Gravity named Holographic Principle.
