Notorious cells

Like students, all cells also undergo various tests; first (sessional exam) the quality assurance test, second (mid-term exam) the duplication test and third (final exam) the alignment test. They are also given a second chance to appear for the tests. Cells are divided into three types based on their performance on tests.

Those cells that demonstrate that they have sufficient knowledge (proteins and enzymes for replication) in the “sessional exam” are allowed to replicate their DNA. The ones failing the test are given a second chance. These cells will go back and prepare the proteins and enzymes required and then undergo a check. Once they are of high enough quality, they can now replicate.

After replication of DNA, they undergo “mid-term exams” where they are checked for their ability to duplicate. Again, some cells will fail, as it is challenging to produce an exact copy of what is learned. It doesn't matter that they fail this second test as they are given another chance. They are given time to prepare and amend their mistakes and once they clear this test, they can now divide.

Finally, when they are dividing, they are given a “final exam” before they divide their content equally among two daughter cells. For this test, chromosomes in the cells have to stand in a straight queue. The cells passing this test divide and result in two daughter cells and the ones that do not pass are given a second chance.

The cells not passing the tests, even in the second attempt, are sent to jail and are sentenced to death. A bit harsh but important for maintaining healthy cells. Sometimes some cells act clever and find shortcuts to the end. This means that they skip their detention and their chance to make amends, and they divide. These notorious cells are called cancer cells. Just as there is not any single reason why students sometimes misbehave, there are many reasons why cells make their control difficult.