The balance between REM and ISREM sleep is maintained by-

Ans. is 'c' i.e., Suprachiasmatic nucleus o A prominent feature of the organization of the sleep and wake is their diurnal rhythim.o The amount of REM slaap reaches its maximum during the late rest phase, whereas NREM sleep peaks in the early rest phase.o This sleep - wake rhythm is a result of the interaction between circadian and homeostatic processes.o Suprachiasmatic nucleus is the centre for maintaining the circadian rhythm and is thus centre for the regulation of the sleep - wake cycle and thus REM - NREM sleep balance.o Circadian clock - suprachiasmatic nucleus promotes REM sleep.