Biology Paper 3 Marking Scheme
KCSE CLUSTER TESTS 16
Biology Paper 3
(a) Specimen R.
Mode of pollination: insect pollination;
Adaptive features; (i) Large petals to make it conspicuous;
(ii) Brightly coloured petals to attract insects.(at distance)
(iii) Specimen SI
Mode of pollination: wind pollination
Adaptive features: (i) Anthers are large attached to long filaments to be easily swayed by wind to disperse pollen grains.
(ii) Stigma is large/feathery/hangs outside the flower to increase surface area for trapping pollen grains in the air.
(b) Stamen are numerous; with fused filaments; to form common/staminal tube;
(c) X - Filament
(d) Class: dicotyledonous (reject wrong spelling)
Reason: five floral parts/petals.
13 marks
(b)
(i) Milk powder.√(1)
(ii) Stomach.√(1)
(iii) Rennin/Pepsin/√(1)
b(ii)tied to b(iii)
(iv) Marasmus.(1)
14 marks
(a)
(i) Flesh;
( ii) It has sharp and curved claws/ talons for grasping the prey;
(b)
(i) 1 Homologous;
ii) 2 Analogous;
(c)
(i) Convergent evolution;
(ii) Divergent/Adaptive Radiation;
(d)
1 - Enable organisms of same embryonic origin to feed on different type of food (reducing competition among organisms and increasing chances of survival);
(e) Pentadactyl limb;
(f) initially all organisms in photograph B had webbed feet; due to staff competition for food they started using feet as peddles in search of food and water; the feet developed/acquired webs, that were transmitted to subsequent generations;
13 marks