AP BIOLOGY

Detailed explanation-1: -The M checkpoint is also known as the spindle checkpoint: here, the cell examines whether all the sister chromatids are correctly attached to the spindle microtubules.

Detailed explanation-2: -The M checkpoint determines whether all the sister chromatids are correctly attached to the spindle microtubules before the cell enters the irreversible anaphase stage.

Detailed explanation-3: -M checkpoint – nuclear division setup check It is also called the spindle checkpoint because the cell examines whether all sister chromatids are correctly attached to the spindle microtubules that separate them. If not, the cell pauses mitosis until all sister chromatids have been attached in the right way.

Detailed explanation-4: -The primary G1/S cell cycle checkpoint controls the commitment of eukaryotic cells to transition through the G1 phase to enter into the DNA synthesis S phase.

Detailed explanation-5: -In mitosis, the spindle assembly checkpoint (SAC) controls the proper attachment to and alignment of chromosomes on the spindle.