June 2018 MS - Component 2 (F) WJEC Biology GCSE
June 2018 MS - Component 2 (F) WJEC Biology GCSE
June 2018 MS - Component 2 (F) WJEC Biology GCSE
SUMMER 2018
GCSE
BIOLOGY - COMPONENT 2
C400U20-1 and C400UB0-1
INTRODUCTION
This marking scheme was used by WJEC for the 2018 examination. It was finalised after
detailed discussion at examiners' conferences by all the examiners involved in the
assessment. The conference was held shortly after the paper was taken so that reference
could be made to the full range of candidates' responses, with photocopied scripts forming
the basis of discussion. The aim of the conference was to ensure that the marking scheme
was interpreted and applied in the same way by all examiners.
It is hoped that this information will be of assistance to centres but it is recognised at the
same time that, without the benefit of participation in the examiners' conference, teachers
may have different views on certain matters of detail or interpretation.
WJEC regrets that it cannot enter into any discussion or correspondence about this marking
scheme.
GENERAL INSTRUCTIONS
Recording of marks
One tick must equate to one mark (except for the extended response question).
Question totals should be written in the box at the end of the question.
Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.
Marking rules
Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.
Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.
A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly,
decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality of the
response. Then decide which mark to award within the level. Award the higher mark in the level if there is a good match with both the content
statements and the communication statement.
Marking abbreviations
The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded.
Marks available
Question
AO1 AO2 AO3 Total Maths Prac
1 (a) (i) Tube x biuret (1) 2 2 2
Tube y iodine (1)
(ii) Protein absent/negative (1) 1 2 2
Starch blue/black colour (1) 1
(b) (i) benedict`s solution (1) 2 3 3
heat strongly/boil (1)
hot water can burn/scald (1) 1
(ii) (Red colour) indicates presence of sugar 1 1 2
(iii) The smoothie contains starch which may have broken down to 1 1
glucose/sugar
Question 1 total 4 4 1 9 0 9
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
2 (a) (i) paper disc/place liquid antibiotic into well (1) 3 3 3
Minimal opening of the lid/lid lifted at angle/work near Bunsen
burner/(1)
Flame forceps/use sterile pipette (1)
(b) (i) 36 -37 1 1
(ii) I C + biggest clear zone on day 1 1 1 1
II B largest clear area at 3 days 1 1 1
o
(c) (i) 35–40 C 1 2 2
Reasons –most suitable for bacterial growth/human body 1
temperature
(ii) Prevents pathogens from {leaving the dish/other bacteria 1 1 1
entering/contamination}
Question 2 total 6 1 2 9 0 8
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
3 QER
(a) Indicative content: 3 3 6
Cortex recognised as outer layer of kidney ,
Medulla recognised in middle region
Cortex darker in colour/medulla lighter colour
Pelvis recognised as white region
part A - ureter
Function of ureter to carry urine(wastes/named waste) away
Part B blood vessel ,
Blood vessels carry blood to and from the kidney
Filtering of blood in kidney
5-6 marks
Most of the indicative content must be included. A and B must be
identified for top band of mark scheme.
There is a sustained line of reasoning which is coherent, substantiated
and logically structured. The information included in the response is
relevant to the argument.
3-4 marks
Three regions within the kidney are named and positions recognised
Relevant reference made to either ureter or blood vessel.
There is a line of reasoning which is partially coherent, supported by
some evidence and with some structure. Mainly relevant information is
included in the response but there may be some minor errors or the
inclusion of some information not relevant to the argument.
1-2 marks
Reference to one/two regions of the kidney and positions recognised,
There is a basic line of reasoning which is not coherent, supported by
limited evidence and with very little structure. There may be significant
errors or the inclusion of information not relevant to the argument.
0 marks
No attempt made or no response worthy of credit.
(b) Risk of infection from fresh animal material. 1 1
Question 3 total 4 3 0 7 0 0
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
(a) I temperature scale 1 4 4
II 6 plots correct = 2marks 2
5 correct = 1 mark
± 1 small square
III line quality 1
(b) (i) Increase in rate of activity then decrease (1) 2 2 2
Reference to 40o C (1)
(ii) 0.27 µmol/min(2) 2 2 2
correct answer without unit (1)
incorrect answer but correct readings and method (1)
(iii) increased kinetic energy/molecules moving faster(1) 2
Increased collisions – (enzyme and substrate) (1) 2
(iv) Any two (x1) from: 2 2
{alters/denatures/destroys} enzyme (1)
shape of active site altered (1)
substrate cannot fit/no enzyme substrate complexes
formed (1)
Question 4 total 4 6 2 12 6 2
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
5 (a) (i) 5 ages, spread throughout the range (15-45). including 15 and 2 2 2
45 (1)
Question 5 total 0 4 4 8 0 6
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
6/1 (a) (i) Contact/aerosols/body fluids/water/insects/contaminated food 1* 1
(ii) Only kill bacteria/do not kill viruses 1 1
(iii) reduced {risk/chance/probability} of {catching the disease/of the 1 1
disease spreading}/less likely to catch disease/
more difficult to catch the disease/
it is more difficult for the disease to spread
(iv) HIV/AIDS weakens immune system/owtte 1 1
(b) (i) Mortality decreases 1 1
(ii) The mortality rate had been decreasing for a long time before
1 1
introduction of vaccine in the UK
(c) (i) 616 400 = 2 marks 2
If incorrect award 1 mark for sight of: 2 2
670 000 x 0.92
(ii) Any one (x1) from: 2
Small number in trial
Ref. conflict of interest/bias
2 2
Any one (x1) from:
Increase sample size
Ref. reproducibility
(d) Any five (x1) from
1. {Inject/introduce} {inactive form/dead} of
{MMR/pathogen/virus}/inject antigen
2. Antigens activate {lymphocytes/WBC}/ref to antigen
recognition(1) 4 1 5
3. Which multiply to form clones (1)
4. Produce antibodies (1)
5. That destroy infecting micro-organisms (1)
6. Memory cells (for measles, mumps and rubella) produced (1)
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
2 (a) Hazard - using sharp scalpel (1) Accept Ref to use of cork borer 2 2 2
Risk – cutting {skin/yourself} while cutting potato and
Control measure – always cut {down/away} from body/onto a
tile (1)
(b) (i) -13.0 = 2 marks 2 2 2
If incorrect award 1 mark for
-13
-13.0435
-0.6/4.6 x100
(ii) Correct plotting (1) ecf 2 2 2
Smooth curve of best fit (1) Accept plot to plot with a ruler
(iii) Water has moved in (1) 2 2 4
From a region of high water concentration to a region of low
water concentration/correct ref. to along water potential
gradient/correct ref. to solute concentrations (1)
Through semi permeable membrane (1)
Osmosis (1)
(iv) 28% + units(1) tolerance ± 1 small square 1 1
(c) (i) Take more readings between 20 - 40% (1) 1 1 1
(ii) Used a balance accurate to 2 decimal places 1 1 1
Question 2 total 4 6 3 13 4 4
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
3 (a) Lock and key 1* 1
(b) (i) Lipase breaks down fat in milk (1) 2 1 3 1
to fatty acid (and glycerol) (1)
Reducing pH/more acidic (1)
(ii) {Lipase/active site/enzyme} has been 1 1 2
{denatured/altered/destroyed}/ cannot form enzyme substrate
complexes (1)
Therefore no reaction/no change in pH/fats have not been
broken down (1)
(c) (i) To allow temperature of the milk to equilibrate with water 1 1 1
bath/OWTTE (1)
(ii) Independent variable: enzyme concentration (1) 2 2 2
Any two controlled variables for 1 mark from:
volume of milk
volume of lipase
temperature
concentration of fat in milk
age of milk
source of milk
Question 3 total 4 0 5 9 0 4
Marks available
Question Marking details AO1 AO2 AO3 Total Maths Prac
Question 4 total 3 4 0 7 3 2
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
5 (a) Indicative content 3 3 6
At the start uptake of A is greater than B
Ref to Active transport
Sulphate is taken up against a concentration gradient
This requires energy/ATP
Seedling A is in aerobic conditions/able to carry out aerobic
respiration
Which produces ATP/releases energy
Seedling B is in anaerobic conditions.
After cyanide, uptake is {at same rate in A and B/reduced in
A/still increasing but at slower rate}/cyanide {reduces uptake in
A/has no effect on B}
Ref. Sulfate up by diffusion in B/Sulfate only taken up by
diffusion in A after cyanide added
5-6 marks
Covers transport methods in both A and B in detail and effect of
cyanide.
There is a sustained line of reasoning which is coherent, substantiated
and logically structured. The information included in the response is
relevant to the argument.
3-4 marks
Covers transport methods in either A or B and some attempt at effect
of cyanide.
There is a line of reasoning which is partially coherent, supported by
some evidence and with some structure. Mainly relevant information is
included in the response but there may be some minor errors or the
inclusion of some information not relevant to the argument.
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
1-2 marks
Covers transport methods in A or B or may give comment on effect of
cyanide.
There is a basic line of reasoning which is not coherent, supported by
limited evidence and with very little structure. There may be significant
errors or the inclusion of information not relevant to the argument.
0 marks
No attempt made or no response worthy of credit.
Question 5 total 3 3 0 6 0 0
Marks available
Question Marking details
AO1 AO2 AO3 Total Maths Prac
6 (a) (i) % cover increases over time 1 1
(ii) To show that it was the efforts at regenerating that was having 1 1 1
an effect/Comparison (qual.)
(b) Any three (x1) from: 3 3
Carbon taken in by plants during photosynthesis (1)
{Converted to/stored as} biomass (1)
{Plants/Biomass}{ does not decompose/remains as peat/does
not decay} (1)
decomposing micro-organisms unable to live in
{acidic/anaerobic} conditions (1)
(c) Decomposers in arable soil/decomposition can occur in arable 3 5 5
soil (1)
Ref. urease (1)
convert of urea to ammonia/urea broken down to ammonia (1) 1
Makes soil less acidic/increases pH(1)
Decomposers not present in soil from Shelf Moor/decomposition
1
cannot occur (1)
ORA
Question 6 total 4 5 1 10 0 5
FOUNDATION TIER
1 (smoothie) 4 4 1 9 0 9
2(bacteria) 6 1 2 9 0 8
3 ( kidney ) 4 3 0 7 0 0
4(enzyme) 4 6 2 12 6 2
5( reactions) 0 4 4 8 0 6
6 (ARTICLE) 6 6 3 15 2 2
TOTAL 24 24 12 60 8(6) 25
HIGHER TIER
1 6 6 3 15 2 2
2 4 6 3 13 4 4
3 4 0 5 9 0 4
4 3 4 0 7 3 2
5 3 3 0 6 0 0
6 4 5 1 10 0 5
Target 24 24 12 60 6 9
TOTAL 24 24 12 60 9 17