Question

Cells from advanced malignant tumors often have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?A) Chromosomally abnormal cells still have normal metabolismB) Cancer cells are no longer density dependentE) Transformation introduces new chromosomes into cellsD) Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.

Answer 1

Answer:

Option- D: Is the best choice to choose from the given options.

Now, let us explain the term Cell cycle in a more comprehensive way.

As the cell cycle is controlled at three checkpoints.

• The integrity of the DNA is assessed at the G₁ checkpoint.

• Proper chromosome duplication is assessed at the G₂ checkpoint.
• Attachment of each kinetochore to a spindle fiber is assessed at the M checkpoint.

Explanation:

The cell cycle is controlled by three internal checkpoints that evaluate the condition of the genetic information.

1. The G₁ Checkpoint:This stage determines whether all conditions are favorable for cell division to proceed. The cell can halt the cycle and attempt to remedy the problematic condition, or the cell can advance into G₀ (inactive) phase and await further signals when conditions improve.
2. The G₂ Checkpoint: The most important role of the G₂ checkpoint is to ensure that all of the chromosomes have been accurately replicated without mistakes or damage.
3. The M Checkpoint:It occurs near the end of the meta-phase stage of mitosis. it determines whether all the sister chromatids are correctly attached to the spindle micro-tubules