This   question was attempted by few candidates  and their performance was poor.  In part  (a)(i) candidates could not list component of the nervous system correctly.  In part (a) (ii) candidates could not  also list causes of mental illness and in  part (a) (iii) candidates could not state ways of preventing mental  illness.  In part (b) (i) candidates were  able to explain what is blood plasma? However, in part (b) (II) candidates  could not list substances found in blood plasma.  In part (c) candidates could not list classes  of drugs.  In part (d) candidates could  not state ways through which country benefits from the activities of WHO.
                    The  expected answers were as follows:
                    (a)(i)  Components of the Nervous System
             -     central nervous system
             -     peripheral nervous system
             -     autonomic/sympathetic and parasympathetic nervous system.
                       (ii)   Causes of Mental Illness
             -     Hereditary factor
             -     environmental factor
             -     emotional problem/stress
             -     using drugs.
   (iii)   Prevention  of mental illness
                    
                      -  engagement in physical activity/recreational  activity
 
                      -  avoidance of peer pressure/bad company
 
                      -  counseling/education
 
                      -  not indulging in drug abuse
 
                      -  frequent medical checkup.
 
                    
                    (b)  (i)   Plasma
               The liquid compound of blood/Fluid  part of the blood.
                        (ii)   Substances found in blood plasma
              -     hormones
              -     food substances/named  e.g  glucose/amino acids/fatty acid and glycerol
              -     urea/waste materials
              -     water
              -     blood proteins e.g. named fibrinogen/antibodies
              -    gases/carbon dioxide/oxygen.
                    (c)  Classes of drugs
                    
                      -   sedatives
 
                      -   narcotics
 
                      -   stimulants
 
                      -   depressants
 
                      -   tranquilizers.                    
 
                    
                    (b)    Ways through which your country benefit from the activities of WHO
                    -     provide teachers to train health worker
                      -     collects and coordinates information and  medical knowledge about health and  
        diseases from the whole world
                      -     institute international sanitation and  quarantine regulations
                      -     prevent the spread of diseases between  countries
                      -     gives advice and practical support to campaigns  to overcome particular diseases/improve
        health
                      -     send medical supplies and team of medical  workers to control epidemics
                      -     provide assistance in funding and  supplying water  to drought – stricken  areas
                      -     when new dams are being built to provide  water, WHO provides expert guidance on 
        measures to be taken to prevent the  spread of schistosomiasis, cholera and other related 
        diseases.
                      -     WHO works in close collaboration with FAO  in planning and running food production 
        programmes where under –nourishment and  malnutrition undermine the health of the 
        community.