The sputum (fluid coughed up from the lungs) of many
smokers contain cells with mutations (errors) in the genes for p53. The smoking induced mutations appear to be an early signal showing that cancer of the lungs will follow. What is the likely relationship between early p53 mutation and the development of lung cancer?

a. p53 with a mutation directly stimulates the growth of cancer cells.

b. Mutations in p53 would prevent abnormal cells from dying by apoptosis.

c. Mutant p53 triggers the M phase of the cell cycle leading to abnormal cell division.

d. p53 causes a cell to enter G0, blocking cell division.

e. both b and c

The correct answer is option b.

Explanation:

The p53 protein is found within the cell's nucleus and is present all over the body. Within the nucleus, the protein combines with the DNA directly. In case, when the destruction of DNA takes place within the cell by certain elements like radiation, toxic chemicals, UV exposure from sunlight, the p53 protein plays an essential role.  

The protein helps in finding whether the DNA can be repaired or the cell needs to go through the process of apoptosis or self-destruction. The p53 protein undergoes DNA repairing by stimulating other genes, however, if the DNA fails to get the repair, it ceases the proliferation of the affected cell and signals it to go through the process of apoptosis. Thus, if a mutation in p53 takes place, the unusual cell will proliferate and eventually results in cancer.  

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.