Candidates’ Name: …………………………………..…………………………..…………………..

 

Random No. Personal No.

Signature: …………………..………………………

 

 

(Do not write your school / Center name or Number anywhere on this booklet)

553/3

BIOLOGY

Paper 2

July / Aug 2024 2 ½ HOURS

 

 

Uganda Certificate Of Education BIOLOGY

Paper 3

TIME: 2 hours 30 minutes

CONFIDENTIAL

Great care should be taken that the information given below does not reach the candidates either directly or indirectly.

 

 

INSTRUCTIONS FOR PREPARING SPECIMENS AND APPARATUS

 

The teacher responsible for preparing specimens must ensure that candidates are provided with correct specimens and other materials as specified in these instructions. Specimens and solutions which have been assigned codes should be presented to candidates using those codes only and not any other identity. The head teacher must ensure that the teacher responsible for preparing the specimens hands in his/her trial results for the physiology/biochemistry question, properly sealed in a separate envelope and firmly fastened (attached) to the candidates’ script envelope(s).

 

In addition to the apparatus ordinarily contained in a Biology Laboratory, each candidate will require;

 

 

Specimen D: Fresh Irish Potato tuber 0.1M Sodium Hydroxide Solution 0.1M Hydrochloric acid Thermometer

Funnel

Motor and Pestle

2 Plastic Beakers (250ml) Hot water

Distilled water 5 test tubes

Test tube holder Filter paper

Access to heat source

All necessary reagents for food test

Specimen P. Freshly Uprooted Couch grass rhizome with at least two shoots Specimen Q. Freshly uprooted black jack (Bidens Pilosa) with fruits

INSTRUCTIONS TO CANDIDATES

This paper consists of two examination items. Answer all the items in the spaces provided.

Drawings should be made in the spaces provided. Use sharp pencils for your drawings. Coloured pencils or crayons should not be used.

No additional sheets of writing paper are to be inserted in the booklet. Work on additional sheets will not be scored.

 

ITEM	SCORE(S)	EXAMINER’S SIGNATURE
Item 1
Item 2
Total

 

 

Item 1

Scientific theories indicate that in the mouth, there is an active substance X which plays a vital role in the process of digestion of food.

The substance works better in slightly alkaline medium within optimum body temperature range between 36⁰C- 40⁰ C. During a science contest, S.2 students were tasked to demonstrate the process of digestion in the mouth using Specimen D, commonly fed on by the people.

 

Task

Determine the composition of food mixture D. Obtain substance X from your mouth and conduct an investigation to demonstrate the effect of X on Specimen D.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Item 2

In Kamuli district, farmers have always had challenges with the weeds that manifest in their gardens even after weeding and clearing has been done. The weeds grow very rapidly and in a short time cover up the entire garden. Specimens P and Q have been collected from the gardens of these farmers.

 

Task

 

• Help the farmers to understand how the specimens are adapted to rapidly growing into new plants in the

 

 

 

 

 

 

 

 

 

 

 

 

• (i) State how the farmers can control specimens P and Q in their

 

 

 

 

 

 

 

 

 

 

TURN OVER

• Draw and label specimen P

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

END