In a typical 7 hour sleep duration, which stage of sleep does adults spent maximum time in?

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 2(25%) and least is stage 1 (5%)NREM- 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)