Search
Free School Management System
Free School Management System for Kenya

Free School Management System

Learn More

KCSE CLUSTER TESTS 15

Biology Paper 3

1.

15 marks

2.

(a). X -Filament√ Rej. Wrong spelling

Function – Attachment of/expose anthers.√

Y – Sepals/calyx√

Function – Protect the flower parts during bloom/during bud development.√

(b). Gamepetalous/fused petal partially√

(c) Sepals are free/ polysepalous.√

(d). Hypogynous ovary/superior ovary.√

(e). (i) -Monocotyledonae√

(ii) -Stamens/anther/filaments are three √

-Petals/sepals are six/multiple of three√

10 marks

3.

(b). No fizzing/no air bubbles form/no effervescence√ 1 mark

(c). Tube B :– Fast reaction√ due to favourable PH for the enzyme catalase reaction/ fizzing/air bubbles produced due to escaping oxygen gas.

Tube D: -No reaction √/fizzing since the enzyme catalase present in specimen P1 has been denatured√ by boiling.

(d). Tube A :– Very slow reaction because of a acidic PH that was unfavorable for the enzyme catalase to react.√1

Tube C: -Very slow reaction because NaOH created an alkaline PH that was unfavourable for the enzyme reaction.√

(e). (i).The rate of reaction will be rapid /will increase /there will be more fizzing.√1

(ii). Grinding releases more catalase√1 enzyme from P1 hence increase in the rate of reaction./Grinding increases√ the surface area over which the enzyme reacts.

(f). Netral /PH-7√

(g). (i). Hydrogen peroxide

(ii).Detoxification√ of hydrogen peroxide.

17 marks

Back Top