If a cell is frozen after 32 divisions, how many divisions will it complete after thawed?

If a cell is frozen after 32 divisions, how many divisions will it complete after thawed?

• A. 18
• B. 16
• C. 32
• D. 50

Answer: (A)

Cells have a finite number of divisions because telomeres shorten with each division, limiting how many times a somatic cell can divide (the Hayflick limit). Freezing preserves the cell’s state but doesn’t reset or repair telomeres, so the remaining divisions after thawing are the total limit minus the divisions already completed. If this cell type has a typical limit of about fifty divisions, having done thirty-two already leaves eighteen more divisions possible. Therefore, it will complete eighteen divisions after thawing. The other numbers don’t fit because they either ignore the finite division limit or imply resetting or a different total capacity.

Cells have a finite number of divisions because telomeres shorten with each division, limiting how many times a somatic cell can divide (the Hayflick limit). Freezing preserves the cell’s state but doesn’t reset or repair telomeres, so the remaining divisions after thawing are the total limit minus the divisions already completed. If this cell type has a typical limit of about fifty divisions, having done thirty-two already leaves eighteen more divisions possible. Therefore, it will complete eighteen divisions after thawing. The other numbers don’t fit because they either ignore the finite division limit or imply resetting or a different total capacity.