This document consists of 9 printed pages and 3 blank pages.
SP (SLM/SLM) T50145/3
© UCLES 2008
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
General Certificate of Education Ordinary Level
READ THESE INSTRUCTIONS FIRST
Write your Centre number, candidate number and name on all work you hand in.
Write in dark blue or black pen.
You may use a pencil for any diagrams, graphs or rough working.
Do not use staples, paper clips, highlighters, glue or correction fluid.
DO NOT WRITE IN ANY BARCODES.
Answer both questions.
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.
Paper 3 Practical Test
1 hour 15 minutes
Candidates answer on the Question Paper.
As specified in the Confidential Instructions.
For Examiner’s Use
© UCLES 2008
1 The maximum size of most living cells is determined by the ratio of their surface area to
their volume. As cells increase in size, their volume increases proportionally more than their
surface area, thus limiting the ability of the surface area to supply the cell with all the nutrients
the cell needs.
You are going to investigate the relationship between the volume and surface area in model
cells made of agar jelly, and the absorption of a liquid by those model cells.
You have been provided with a block of red-coloured agar, measuring approximately
3 cm × 1 cm × 1 cm, labelled A1.
You have also been provided with a solution, labelled A2.
Read through the following instructions before you attempt question (a).
Using a sharp knife or scalpel, cut the agar block into three
cubes, each approximately 1 cm × 1 cm × 1 cm.
Place one of these cubes into a large test-tube.
Cut one of the remaining cubes into 8 blocks so that each
block is approximately 0.5 cm × 0.5 cm × 0.5 cm.
Put all 8 blocks into another large test-tube.