Question

in an otherwise normal cell, what happens if one mistake is made during dna replication?
mistakes are never made during dna replication.
the cell will begin to divide uncontrollably, forming a malignant tumor.
nothing; mistakes just happen.
a cell cycle checkpoint detects the error and pauses the cell cycle so the error can be corrected.
the mutation will be inherited by the individuals offspring.

Explanation:

• DNA replication is a highly accurate process, but mistakes can occur. However, cells have mechanisms to deal with errors.
• The first option is incorrect because mistakes can be made during DNA replication.
• The second option is an extreme outcome that usually doesn't happen with just one mistake. Uncontrolled division (cancer - like behavior) is more likely due to a series of accumulated mutations.
• The third option is incorrect. Cells have quality - control mechanisms and don't just ignore mistakes.
• The fourth option is correct. Cell cycle checkpoints (such as the G1/S, S, and G2/M checkpoints) can detect DNA replication errors. When an error is detected, the cell cycle is paused to allow for DNA repair.
• The fifth option is incorrect. Somatic cell mutations (mutations in non - germ cells) are not inherited by offspring. Only mutations in germ cells (sperm and egg cells) can be passed on to offspring.

Answer:

A cell cycle checkpoint detects the error and pauses the cell cycle so the error can be corrected.