Cancers are groups of cells that divide rapidly and uncontrollably. Thus cancer cells
Select one:
a. are stuck at the metaphase plate.
b. never enter the cell cycle.
c. have a relatively short G1 phase and ignore the G1 and G2 checkpoints.
d. are always in the G0 phase.
Got my grade, the answer is definitely C
c is my choice
c. have a relatively short G1 phase and ignore the G1 and G2 checkpoints.
The correct answer is c. have a relatively short G1 phase and ignore the G1 and G2 checkpoints.
To understand why cancer cells have a relatively short G1 phase and ignore the G1 and G2 checkpoints, let's first talk about the cell cycle. The cell cycle is a series of events that cells go through in order to grow and divide. It consists of four main phases: G1 phase, S phase, G2 phase, and M phase (which includes mitosis and cytokinesis).
During the G1 phase, the cell grows and prepares for DNA synthesis. At the end of the G1 phase, there is a checkpoint called the G1 checkpoint. This checkpoint functions as a control mechanism to ensure that the cell has the necessary nutrients, growth factors, and DNA integrity before entering the next phase. If there are any issues or errors detected during this checkpoint, the cell cycle can be paused, allowing for repairs or triggering cell death if necessary.
After passing the G1 checkpoint, the cell enters the S phase, where DNA replication occurs. Following S phase, there is another checkpoint called the G2 checkpoint. At this checkpoint, the cell checks if DNA replication is complete and looks for any DNA damage. If everything is in order, the cell proceeds to the final phase of the cell cycle, M phase.
Now, when it comes to cancer cells, they have certain characteristics that distinguish them from normal cells. One of these characteristics is uncontrolled cell division. Cancer cells divide rapidly and continuously, without any proper regulation or control. This uncontrolled division is due to abnormalities in the genes that regulate the cell cycle.
Specifically, cancer cells often have abnormalities in genes that control the G1 and G2 checkpoints. These abnormalities can lead to a relatively short G1 phase, where the cancer cells quickly progress through this phase and enter the S phase, even if the necessary conditions or proper genetic integrity are not met. By doing so, cancer cells bypass the normal regulation of the G1 checkpoint. They also tend to ignore the G2 checkpoint, allowing damaged DNA to go undetected and pass on to the next phase of the cell cycle.
In summary, cancer cells have a relatively short G1 phase and ignore the G1 and G2 checkpoints due to abnormalities in genes that regulate these checkpoints. This uncontrolled progression through the cell cycle contributes to their rapid and uncontrollable division.