This question was attempted by many candidates and their performance was poor. Candidates wrote wrong answers such as reduces pain, helps to maintain appetite, it changes chemicals of the body, it helps the blood to flow well and it brings the temperature down as ways in which sleep is important to human. 

However the expected answers are as follows:

• WAYS IN WHICH SLEEP IS OF IMPORTANCE TO HUMANS
• helps in relaxing muscles
• helps in lowering blood pressure
• improves general well being
• conserves energy
• aids work/organs (named) efficiency
• reduces tension/stress in humans/relaxes the brain
• accelerates removal of wastes
• aids food digestion