-
7/29/2019 DPOL'09-6.doc
1/9
DHARUMAVANTHA SCHOOL EXAMINATIONS
Preliminary Ordinary Level 2009
BIOLOGY
Paper 6 Alternative to Practical
Candidate answer on the Question Paper
READ THESE INSTRUCTIONS FIRST
Write your name, centre number and candidate number in the
spaces at the top of this page.
Write in dark blue or black pen in the spaces provided on the
Question paper.
You may use a soft pencil for any diagrams, graphs or rough
working.Answerall questions.The number of marks is given in
brackets [ ] at the end of each question or part question.
For Examiners Use
1
2
3
TOTAL
5090/06
August/September2009
1 hour
CANDIDATENAME
CENTRENUMBER
CANDIDATENUMBER
This question paper consists of 9 printed pages.
[Turn over
DHARUMAVANTHA SCHOOL
E x a m i n a t i o n s
DSE 2009
-
7/29/2019 DPOL'09-6.doc
2/9
DSE 2009
2
1. An experiment was carried out as part of an investigation on
the effects of exercise. Fivestudents took a piece of filter paper,
which measured 4 cm by 4 cm. Each piece of paperwas weighed and
then placed against the forehead of a student using a piece of
ploytheneto hold it. The paper was left for five minutes, which the
student was sitting still, and thenreweighed.
The filter paper was then replaced on the forehead but during
the next five minute period thestudent ran on the spot. At the end
of the second five minutes the paper was reweighed again.The
results are shown in the table 1.1 below.
Table 1.1
(a) (i) Complete the table by calculating the mean values. Show
your working.
At start:..
After contact with forehead when sitting:..
After contact with forehead during exercise:. [2]
5090/06/DPOLE/09
For examinuse
-
7/29/2019 DPOL'09-6.doc
3/9
DSE 2009
3
(ii) Explain why the mass of the paper increased as a result of
the paper being held on theforehead?
[2]
(iii) Use the data in the table 1.1 to explain the effect of
exercise on the change in the massof the paper.
[4]
(b) Suggest why five students were used to perform the
experiment rather than taking theresults from just one student?
[2] [Total: 10]
5090/06/DPOLE/09
For examuse
-
7/29/2019 DPOL'09-6.doc
4/9
DSE 2009
4
2. Two uncooked hens eggs of similar size were submerged in acid
to dissolve the shell. Thecontents of the eggs are left intact,
enclosed by the egg membrane.
One de-shelled egg has been placed in distilled water for 2
days. The other egg has beenplaced in salt solution for 2 days.
Fig. 2.1 shows the two eggs after two days.
Fig. 2.1
(a) (i) Complete Table 2.1 to compare the two eggs.
Table 2.1
(ii) Suggest an explanation for these differences.
.... [2]
5090/06/DPOLE/09
For examineuse
-
7/29/2019 DPOL'09-6.doc
5/9
DSE 2009
5
(b) A student carried out a similar experiment and varied the
concentration of salt indifferent solutions.
Table 2.2 shows the percentage change in mass of the eggs after
2 days. Table 2.2
(i) Draw a fully labeled graph of this data on the axes.
[5]
5090/06/DPOLE/09
For examinuse
-
7/29/2019 DPOL'09-6.doc
6/9
DSE 2009
6
(ii) Determine the concentration of salt solution where there is
no change in mass.
[1]
(iii) Explain why there is no change in mass at this
concentration of salt solution.
[2]
(c) Describe a food test which might show whether there is more
protein to be found in thewhite or in the yolk of the egg.
[3] [Total: 16]
5090/06/DPOLE/09
For examuse
-
7/29/2019 DPOL'09-6.doc
7/9
DSE 2009
7
3. You are provided with an active yeast culture in a test-tube
with a delivery tube attached.You are also provided with a
test-tube containing hydrogencarbonate indicator whichshould be a
red solution.
Fig.3.1 shows the apparatus fixed with given materials.
Fig. 3.1
Hydrogencarbonate indicator changes colour according to pH. In
alkaline solutions theindicator becomes purple and in acidic
solutions the indicator becomes yellow.
(a) Describe the appearance of the yeast culture.
[1]
(b) Explain the changes which occur in the test-tubes.
[3]
5090/06/DPOLE/09
For examuse
-
7/29/2019 DPOL'09-6.doc
8/9
DSE 2009
8
(c) Describe how you would collect and measure the volume of gas
given off per minute by20 cm3 of the active yeast culture.
[3]
(d) Fig. 3.2 shows a yeast cell reproducing asexually.
5090/06/DPOLE/09
For examuse
-
7/29/2019 DPOL'09-6.doc
9/9
DSE 2009
9
(i) Make a labelled drawing of the yeast cell.
[3](ii) Measure the diameter of the yeast cell in Fig. 3.2
between points X and Y.
diameter of cell [distance between X and Y]
Calculate the magnification of your drawing.
Show your working
Magnification. [2]
(e) Describe how the experiment results in Fig. 3.1 can be
applied in bread making?
[2][Total: 14]
GOOD LUCK
5090/06/DPOLE/09
For exaus
