Observation

This question was attempted by many candidates and their performance was very poor.  In part (a)(i) candidates left the question unanswered and in (a)(ii) candidates could not state effects of malnutrition in humans.  In part (b) candidates wrote answer that the organs hand E muscle to brain and the brain send the message back E the muscle.  In part (c) candidates correctly stated ways of preventing tooth decay
However, the expected answers are as follows:

(9)(a)   MALNUTRITION
is a condition occurring in humans in which there is lack of required food nutrients; in         their correct amount/proportion.
 
(ii)    EFFECTS OF MALNUTRITION IN HUMANS

• death
• fluid imbalance
• chronic diseases/goiter/kwashiorkor/named deficiency diseases
• growing lean/emaciation/weight loss
• retarded growth/delayed development
• stunted growth
• stunted intellectual development
• general body weakness/reduced ability to work
• reduce immunity/vulnerability
• depression/apathy/introversion.

 (b)        MECHANISM INVOLVED IN ACTION OF A BOY THAT TOUCHED A HOT OBJECT AND QUICKLY WITHDREW HIS HAND
-           the temperature/ heat receptors of the hand are stimulated
-           and impulse/message is passed along the sensory neurone
-           to the spinal cord
-           through the dorsal root
-           the impulse/message moves over a synapse
-           and stimulate a relay/intermediate/nerve or neuron
-           the impulse moves across a synapse to motor neuron
-           the impulse leaves the spinal cord through ventral root organ
-           to the effector organ/muscles of the hand
-           which contracts and pulls the hand away from the hot object.
 
(c)     WAYS OF PREVENTING TOOTH DECAY

• teeth must be kept cleared/brushed after meals
• use chewing stick to clean the teeth every day
• avoid eating too much sweet/sugary substances
• regular visit/examination by the dentist
• reduce intake of carbonated drinks/named
• eat food rich in calcium/phosphorus/balance diet
• avoid eating too hot or cold food to prevent cracking of the teeth
• avoid using the tooth to open bottle tops
• use fluoride tooth paste/drink fluorinated water
• avoid using sharp pointed objects to pick the tooth/use dental floss
• proper brushing of the teeth up and down.