Biology 0610/53 May/June 2021: question paper and mark scheme
Cambridge IGCSE Biology (0610), Paper 5 Practical Test, May/June 2021. Read both free below, or download them. Done the paper? Get it marked by AI against this mark scheme.
Vitamin C is an important component of a balanced diet. Many health drinks contain vitamin C.
You are going to estimate the concentration of vitamin C in a health drink by comparing it to solutions with known concentrations of vitamin C.
DCPIP is an indicator for vitamin C. When added to a vitamin C solution, the blue DCPIP reacts with vitamin C and becomes colourless. Drops of DCPIP are added to the vitamin C solution until the solution remains blue.
Read all the instructions but DO NOT CARRY THEM OUT until you have drawn a table for your results in the space provided in 1(a)(ii).
You should use the safety equipment provided while you are carrying out the practical work.
Step 1 Label four small beakers A, B, C and D.
Step 2 Use the large syringe and the information in Table 1.1 to make the vitamin C solutions in the four labelled beakers.
Table 1.1
volume of 1.00% vitamin C volume of final percentage beaker solution / cm3 water / cm3 concentration of vitamin C
A 1 3 0.25
B 2 2 0.50
C 3 1
D 4 0 1.00
(a) (i) Complete Table 1.1 by calculating the final percentage concentration of vitamin C in beaker C.
……% [1]
Step 3 Label four test-tubes A, B, C and D and place them in a test-tube rack.
Step 4 Use the small syringe to transfer 0.5 cm3 of vitamin C solution from beaker A to test-tube A.
Step 5 Repeat step 4 using beaker B and test-tube B.
Step 6 Repeat step 4 using beaker C and test-tube C.
Step 7 Repeat step 4 using beaker D and test-tube D.
Step 8 Fill the dropping pipette with the DCPIP solution.
Step 9 Put one drop of DCPIP into test-tube A and swirl gently to mix.
The blue colour should disappear as the vitamin C reacts with the DCPIP. You will be counting the number of drops of DCPIP you put into the test-tube.
Step 10 Repeat step 9 until the blue colour does not disappear and the solution remains blue.
Step 11 Record, in your table in 1(a)(ii), the total number of drops of DCPIP you have put into test-tube A.
Step 12 Repeat step 8 to step 11 with test-tubes B, C and D.
(ii) Prepare a table to record your results.
[4]
(iii) State a conclusion for your results.
…… [1]
Step 13 Label a clean test-tube H.
Step 14 Use the small syringe to put 0.5 cm3 of health drink H into test-tube H.
Step 15 Add drops of DCPIP and swirl gently until the colour in the test-tube remains blue.
(iv) Record the number of drops of DCPIP you added to test-tube H.
…… drops [1]
(v) Estimate the percentage concentration of vitamin C in health drink H using your results from 1(a)(ii) and 1(a)(iv).
…… % [1]
(vi) Identify two variables that were kept constant in this investigation.
1 ……
2 ……
[2]
(vii) Explain why it was important to swirl the contents of the test-tube after adding each drop of DCPIP in step 9.
…… [1]
(b) Repeating the investigation would improve the method used.
Suggest two other improvements to the method that would allow a more accurate estimation of the concentration of vitamin C in health drink H.
1 ……
2 ……
[2]
(c) Explain why counting the number of drops of DCPIP is not accurate.
…… [1]
(d) The manufacturers of health drink H claim that it also contains protein and glucose.
Describe how you would test health drink H for protein and glucose.
Include the results for a positive test.
protein ……
glucose ……
[5]
[Total: 19]
Mark scheme
1(a)(i) 0.75 (%) ; 1
1(a)(ii) table with minimum two columns and a header row ; 4
suitable headings ; MP2 vitamin C, percentage / concentration,
or beaker and (number of) drops (DCPIP)
four values recorded ;
expected trend: more drops for D (1%) than A (0.25%) ; check supervisor’s report
1(a)(iii) higher concentrations of vitamin C require greater number of drops of 1 ecf candidate’s results in 1(a)(ii)
DCPIP ; ora
1(a)(iv) a number recorded ; 1
1(a)(v) value calculated from the candidate’s results ; 1
1(a)(vi) any two from: 2
concentration of DCPIP ;
(final) volume of vitamin C solution ;
type of indicator ;
1(a)(vii) to mix the contents / so that all of the DCPIP reacts with the vitamin C / to 1
allow time for the solution to go colourless / AW ;
1(b) any two from: 2
use intermediate concentrations / AW ;
measure the volume of DCPIP instead of drops ;
use a larger volume of vitamin C / lower DCPIP concentration ;
keep temperature constant ;
AVP ; e.g. plot, results / values, on a graph and read off value from a line of
best fit
1(c) any one from: 1
drop size is variable / unknown drop size ;
unable to determine exact end-point as maybe between two drops / AW ;
difficult to count the number of drops ;
1(d) protein 5
biuret (solution / reagent) ;
purple colour ;
glucose
Benedict’s (solution / reagent) ;
heat ;
(brick-)red / orange / yellow / green, colour ;
(a) You are provided with the leaf of a plant, L1.
(i) Make a large drawing of leaf L1.
[4]
(ii) Measure the length of your drawing in 2(a)(i). Include the unit.
Indicate on your drawing where you measured this length.
length of the leaf in your drawing ……
Measure the actual length of the leaf L1. Include the unit.
actual length of leaf L1 ……
Calculate the magnification of your drawing using the equation: length of the leaf in your drawing magnification = actual length of leaf L1
[3]
(b) A student used an aquatic plant to investigate the effect of carbon dioxide concentration on the rate of photosynthesis. The production of oxygen gas can be used as an estimate of the rate of photosynthesis.
The student set up the apparatus shown in Fig. 2.1. He counted the number of bubbles produced in 5 minutes. The carbon dioxide concentration in the water around the aquatic plant was 2 mg per dm3.
He repeated the experiment with five different concentrations of carbon dioxide.
bubbles containing oxygen gas
aquatic plant
lamp water
Fig. 2.1
The student’s results are shown in Table 2.1.
Table 2.1
carbon dioxide concentration number of bubbles
/ mg per dm3 produced in 5 minutes
2 4
4 14
6 20
8 25
10 35
12 35
(i) Plot a line graph on the grid of the data in Table 2.1.
[4]
(ii) Describe the trend shown on your graph in 2(b)(i).
…… [1]
(iii) The rate of photosynthesis can be given as the number of bubbles produced in one minute.
Use the information in Table 2.1 to calculate the rate of photosynthesis at a carbon dioxide concentration of 4 mg per dm3.
Give your answer to one significant figure.
Space for working.
…… bubbles per minute
[2]
(iv) Identify the variable that the student changed in this investigation (the independent variable).
…… [1]
(c) Counting bubbles is not an accurate method for measuring the volume of gas produced by a plant during photosynthesis.
Plan an investigation to determine the effect of light intensity on the rate of photosynthesis.
Your plan should include a more accurate method of measuring the volume of gas produced during the reaction.
…… [6]
[Total: 21]
Mark scheme
2(a)(i) Size – more than 50% of answer gap used ; 4
Quality – continuous outline , no shading ;
Details ;; see supervisor’s report
2(a)(ii) measurement indicated on candidate’s drawing ; 3
correct measurement of line on drawing ;
magnification calculated from candidate drawing and measurements ;
2(b)(i) axes labelled with units ; 4 (number of) bubbles in 5 minutes + carbon
dioxide concentration , mg per dm3
linear scale for plotted points to occupy half or more of the grid in both
dimensions ;
all plotted points accurate to ± half a small square ;
line with no extrapolation and points joined with a ruler ; A line of best fit
2(b)(ii) as carbon dioxide concentration increases, the number of bubbles increases 1
(and levels off) / ora ;
2(b)(iii) 3 (bubbles per minute) ;; 2 MP1 correct rate calculation i.e.
14÷5 = 2.8 (bubbles per minute)
MP2 correct rounding to one significant
figure
2(b)(iv) carbon dioxide concentration ; 1
2(c) any six from: 6
independent variable:
1 at least two light intensities stated ;
given method:
2 set up lamp with plant in water ;
new method:
3 use a ruler to measure distance of lamp ;
4 change distance of lamp / bulb wattage / AW ;
5 use of a heat shield ;
6 ref. to equilibration time ;
7 ref. suitable apparatus for collecting gas e.g. gas syringe / (inverted)
measuring cylinder / photosynthometer ;
8 measure volume in set time / record time to produce set volume ;
9 &10 controlled variables ;;
max two from:
temperature
type / species, of plant
number of leaves / leaf surface area / size / mass
pH
carbon dioxide concentration
volume of water
11 relevant safety precaution ; e.g. ref. electric lamp and water
12 repeat the whole investigation at least two more times ;
Checked your answers against these? Let AI mark the whole paper, on your own working.
Examiners follow the generic marking principles at the front of the scheme, then each question's points: method (M), accuracy (A) and independent (B) marks, error carried forward where the scheme allows it, and positive marking, so you're credited for what you got right.
Check your answers against it
Done this paper? Upload your script and CIE Buddy's AI marker marks it question by question against this exact scheme, puts the ticks on your own working and says what each lost mark needed.
Where can I find the 0610/53 May/June 2021 mark scheme?+
On this page, free: the mark scheme for IGCSE Biology 0610/53, May/June 2021 (0610_s21_ms_53), and the question paper (0610_s21_qp_53), to read or download, with each question's marking points written out underneath.
How many marks is 0610/53 out of?+
Biology 0610/53 for May/June 2021 is out of 40 marks, with 1 hour 15 minutes to answer it, across 2 questions.
Can I get my 0610/53 answers marked?+
Yes. Upload your answers to 0610/53/M/J/21 as a PDF or photos, and CIE Buddy marks every question against this paper's official mark scheme, using Cambridge's marking rules. You get your score, each lost mark explained on your own script, and the topics to revise. It's a guide, not an official Cambridge grade.