This question was attempted  by many candidates and their performance was good.  In part (a) candidates correctly listed types  of worms that infest humans with wrong spellings. 
                    In part (b)  candidates also stated effects of worm infestation in humans.  In part (c) candidates correctly listed types  of worms that infest humans but with wrong spellings. 
                    In part (b)  candidates also stated effects of worm infestation in humans.  In part (c) candidates correctly enumerated  ways by which worm infestation could be prevented in humans.  In part (d) candidates also correctly  described how water is purified for supply but some candidates were not able to  describe the process of water purification sequentially. 
                    The expected  answers however are as follows: 
                    1(a)      TYPES  OF WORMS 
                    
                      - thread worm
 
                      - roundworm
 
                      - guinea  worm
 
                      - hook  worm
 
                      - flatworm/tape  worm
 
                      - filarial  worm
 
                     
                      
                    (b)        EFFECTS  OF WORM INFESTATION IN HUMANS 
                    
                      - blood  stain in faeces
 
                      - emaciation/weight  loss/ poor growth/deprive humans of nutrients
 
                      - anaemia/paleness
 
                      - abdominal  pains
 
                      - loss of  appetite
 
                      - loss of  sight 
 
                      - bloated  abdomen
 
                      - indigestion  / constipation
 
                      - vomiting
 
                      - body  itching /nervous disorders
 
                      - weakness
 
                      - cause  diseases
 
                      - leads to  death if not treated 
 
                     
                      
                     (c)       WAYS OF PREVENTING WORM INFESTATION IN  HUMANS 
                    
                      - proper  hygiene
 
                      - regular  deworming
 
                      - good  knowledge of Health Education
 
                      - proper  cooking of foods
 
                      - elimination  of primary and secondary hosts/vectors
 
                      - proper  sewage disposal
 
                      - drink  clean water
 
                      - avoid  walking bare footed in infested areas/media
 
                     
                      
                                (d)       DESCRIPTION  OF WATER  PURIFICATION  FOR 
                                              A TOWNSHIP SUPPLY 
                    
                      - river  water is pumped into tank of filter beds 
 
                      - the  filter beds removes the debris
 
                      - alum is  added to quicken the rate of sedimentation
 
                      - resulting  water is treated with carefully controlled quantity of chlorine
 
                      - to kill  the harmful germs
 
                      - the  treated water is pumped into a storage tank
 
                      - from  where it is carried in pipes for supply to township
 
                      |