Smoking is known to induce mutations in a particular gene (let's call it gene X) with a key regulatory role in the cell cycle. This mutation in gene X can be detected by isolating cells from the sputum (fluid coughed up from the lungs) of many smokers, and is used as a hallmark to diagnose lung cancer. Which of the following gives a most likely explanation for the relationship between a mutation in gene X and the development of lung cancer? a. gene X codes for a protein that initiates the entry of cells into M-phase of the cell cycle.
b. gene X codes for a protein that allows the entry of cells into S-phase after making sure that all the necessary building blocks and nucleotides have been made by the cell during G1 phase.
c. gene X codes for a protein that plays a role in the formation of the cleavage furrow during cytokinesis.
d. gene X codes for a protein that plays a role in the entry of cells into S-phase of the cell cycle.
e. gene X codes for a protein that prevents cells from entering M-phase until all errors encountered during DNA replication are corrected.