Biology Paper 3 Question Paper
KCSE CLUSTER TESTS 15
Biology Paper 3
You are provided with a food substance labeled solution G. The reagents provided are Iodine solution, Benedicts solution, 2M hydrochloric acid, 10% sodium bicarbonate, 1% copper II Sulphate and 10% sodium hydroxide solution. Perform the food tests and fill in the table below.
15 marks
A student observed and drew a flower as shown below.
a) Name the following parts and state their functions. (4mks)
X....................................................................................................................................
Function......................................................................................................................... ..........................................................................................................................................
Y....................................................................................................................................... Function............................................................................................................................ ..........................................................................................................................................
b) Briefly describe the nature of the corolla of the flower drawn. (1mk) .......................................................................................................................................... ..........................................................................................................................................
c) Briefly describe the nature of the calyx of the flower drawn. (2mks) .......................................................................................................................................... ..........................................................................................................................................
d) What type of ovary does the flower have? (1mk)
..........................................................................................................................................
e) i) To which class does a plant with this type of a flower belong? (1mk) ..........................................................................................................................................
ii) Give one reason to support your answer in (e (i) ) above. (1mk) ..........................................................................................................................................
10 marks
You are provided with: a specimen labeled P1
- 15ml of 3% hydrogen peroxide.
- Dilute hydrochloric acid.
- Dilute sodium hydroxide.
- Distilled water.
- Means of heating.
- Means of labeling.
- Test tube holders.
- Scapel.
- Four boiling tubes.
- A ruler.
Prepare four boiling tubes and label them A,B,C and D.
Boiling tube A - Add 3mls of 3% Hydrogen peroxide +2mls dil. Hcl
Boiling tube B – Add 3mls of 3% Hydrogen peroxide + Distilled water
Boiling tube C- Add 3mls of 3% hydrogen peroxide + Dilute NaOH
Boiling tube D – Add 3mls of 3% hydrogen peroxide + Distilled water.
a) From specimen P1 provided, cut 4 cubes of 1cm x 1cm x1cm.
Drop one piece in each of the test tubes A B and C
Record your observations in the table below. (3mks)
b) Boil the fourth cube of specimen P1 in water in a boiling tube for 3 minutes. Remove it from water, cool it and drop it in tube D. Record your observations. (1mk) ...............................................................................................................................................
c) Account for your results in tube B and D. (4mks)
B................................................................................................................................................. .................................................................................................................................................... D................................................................................................................................................. ....................................................................................................................................................
d) Account for the results in tubes A and C. (2mks) A.................................................................................................................................................. ............................................................................................................................................... C................................................................................................................................................. ...............................................................................................................................................
e) i) What would be the effect of grinding specimen P1 on the rate reaction in tube B. (1mk) ............................................................................................................................................... ...............................................................................................................................................
ii) Give a reason for your answer in e (i) above. (2mks)
............................................................................................................................................... ..............................................................................................................................................
f) Suggest the optimum PH for the enzyme reaction in this experiment. (1mk) ............................................................................................................................................... ...............................................................................................................................................
g) i) Give a word equation for the reaction between hydrogen peroxide and catalase enzyme. (2mks) ............................................................................................................................................... ...............................................................................................................................................
ii) What’s the significance of the above reaction in living organism? (1mk) ............................................................................................................................................... ...............................................................................................................................................
17 marks