The exact location of the checkpoint was not disclosed.
The exact topology of the checkpoint network is unknown, so that the way in which signal amplification is achieved remains unclear.
Whereas the role of MAD2 in mitotic spindle checkpoint control is well-documented, the exact role of MAD2B still remains to be established.
Overall, although the exact mechanism leading to activation of intra-S checkpoint signaling remains to be elucidated, ATM/Tel1 and ATR/Mec1 signaling following DNA damage modulate the rate of DNA synthesis and recombinational repair.
The exact relationship between tension-dependent error correction and checkpoint status is elusive (Khodjakov and Rieder, 2009; Nezi and Musacchio, 2009; Santaguida and Musacchio, 2009; Khodjakov and Pines, 2010; Lampson and Cheeseman, 2010; Maresca and Salmon, 2010).
She records the exact amount of time Palestinians spend waiting at Israeli checkpoints.
Several mechanisms of p53 activation that suggest a special checkpoint controlling ribosomal biogenesis have been proposed, but the exact mechanism remains unclear (Fumagalli and Thomas, 2011).
For example, the exact number of Cdc20 molecules that need to be sequestered during spindle assembly checkpoint activation has not been measured.
Although the exact function of BRCA1 remains to be defined, roles in DNA damage repair, cell cycle checkpoint control, transcriptional regulation and, more recently, ubiquitination have been inferred.
According to the magazine, the plans included "the exact function of every single room, the thickness of each wall, the exact position of every toilet and every emergency exit and every security checkpoint".
