<prompt> In a typical 7 hour sleep duration, which stage of sleep does adults spent maximum time in?Stage 1 NREMStage 2 NREMStage 3 NREMREM  <response>: Ans. B. Stage 2 NREM In adults REM sleep occupies approximately 25 of the total sleep time infants- 50 NREM sleep occupies approximately 75 of the total sleep time. Stage 2 NREM occupies the maximum duration 45 followed by stage 225 and least is stage 1 5NREM- REM cycle We first enter NREM sleep, then we pass through stages 1 and 2, and then we spend about 70-100 min in stages 3 and 4. After this the sleep lightens and then we enter REM sleep This cycle is repeated at an interval of 90-110 minutes Ultradian rhythm 