K.C.S.E Biology Q & A - MODEL 2013PP2QN03

K.C.S.E Biology Q & A - MODEL 2013PP2QN03

(a) Explain the importance of the following in photosynthesis: 
(i) light;
(ii) carbon(IV) oxide;
(iii) chlorophyll.

(b) Name one appropriate food substance for each of the following enzymes: 
(i) ptyalin 
(ii) pepsin
(c) State the cause and two symptoms of Ben-ben.
 Cause             
Symptoms ​

answers

​(a) (i) Provides energy needed to split water molecules into oxygen and hydrogen/photolysis;
Provides energy for formation of ATP molecules (which is used in dark stage)
(ii) Combines with hydrogen ions to make glucose;
(iii) Used to trap light energy;
(b) (i) Starch;
(ii) Protein;
(c) (i) Lack of vitamin B1/thiamine; 
(ii) . Stunted growth;
 Paralysis of legs/arms/limbs/damage to peripheral nerves;
Heart failure
 Swelling of  feet/oedema
 Gastrointestinal disturbances/loss of appetite/constipation/diarrhoea/vomiting;
 Weight loss/muscle wasting
 Pale skin