Reference(s) H. Lodish , A. Berk , S. L. Zipurursky , P. Matsudaria , D. Baltimore and J. Darnell, Molecular Cell Biology, W. H. Free Man and Company, 2000. B. Alberts, A. Johnson, J. Lewis, M. Raff, K. Roberts, and P. Walter, Molecular Biology of the Cell, Garland Science, 2002. S. C. Rastogi , Cell Biology, India: New Age International Pub. Ltd., 2001. E. D. P. Robertis De and E. M. F. Robertis De, Cell and Molecular Biology, B.I. Publications, Pvt. Ltd., 2005. Gerald Karp and Nancy L. Puritt , Cell and Molecular Biology, Concepts and experiments, John Wiley and Sons Inc., 2004. 1/5/2017 Cell Cycle 20