Task 1. Genes that were to be expressed in the S period remained inactive. Will this affect the course of mitosis? Name the genes controlling the S period. Explain their mechanisms.
If the cell has not properly copied its chromosomes, an enzyme called cyclin dependent kinase, or CDK, will activate the cyclin, and the cell cycle will not proceed to the next phase. The cell will undergo cell hello. Two classes of genes, oncogenes and tumor suppressor genes, link cell cycle control to tumor formation and development. Oncogenes in their proto-oncogene state drive the cell cycle forward, allowing cells to proceed from one cell cycle stage to the next.