A-LEVEL BIOLOGY MARK SCHEME
Practice Paper 1 Maximum marks: 91
View detailed guidance on the conclusions you can draw from your students' performance in
these papers on the MERiT welcome page. Understand how your students compare with
others and target revision effectively by entering marks into MERiT.
1 (a) (i) fructose; 1
(ii) correctly drawn (OH group at bottom left); 1
(b) hydrolysis; 1
(c) (i) heat with Benedict’s solution (disqualify if HCl added);
orange / brown / brick red / green / yellow colour or precipitate; 2
(ii) biuret test / NaOH + CuSO4;
purple / violet / lilac / mauve; 2
(d) Starch (max 3)
1. Context of storage for starch, structure for cellulose
2. Helical/ spiral shape so compact;
3. Large (molecule)/insoluble so osmotically inactive;
Accept: does not affect water potential/ψ.
4. Branched so glucose is (easily) released for respiration;
Ignore: unbranched.
5. Large (molecule) so cannot leave cell/cross cell-surface membrane;
Cellulose (max 3)
5. Long, straight/unbranched chains of β glucose;
6. Joined by hydrogen bonding;
Note: references to ‘strong hydrogen bonds’ disqualifies this
mark point.
7. To form (micro/macro)fibrils;
8. Provides rigidity/strength; 5 max
[Total 12 marks]
Page 1
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, 2 (a) (i) break open cells / release cell contents; 1
(ii) keep pH the same / controls pH;
prevent change to / denaturing of proteins / enzymes; 2
(b) (i) 2
(supernatant) C (pellet) B; (pellet) A;
(ii) site of respiration which releases energy / ATP; 2
required for movement against concentration gradient;
ignore first point for thermodynamically incorrect statements
such as “making energy”.
[Total 7 marks]
3 (a) Bacteria killed; 1
Ignore: no growth or growth of bacteria prevented.
Accept: bacteria destroyed.
Accept: no living bacteria.
(b) Clear zone would be too large 1
OR Clear zones would overlap/merge
OR Could kill all bacteria (on the plate);
Must convey idea of too large.
(c) 1. (Same) size; 2 max
Accept: any measure of size e.g. thickness, area, diameter.
Ignore: ‘same shape’ as shape shown on the diagram.
2. (Same) material/absorbency;
3. In solution for same time period;
Ignore: reference to volume of disinfectant.
(d) Any number between 2.5 to 3.2 = two marks; 2
student has to use r squared to compare the areas of the cleared zones
Allow one mark for an incorrect answer but shows method of
calculating how many times more effective D is than B
e.g. 21/22 divided by 13/14
or 10.5/11 divided by 6.5/7
or 1.57/1.6/1.69/1.7.
[Total 6 marks]
4 (a) (i) 1.08; 1
Must be to 3 significant figures, as in the table
(ii) (Allows) 2
Accept: outliers instead of anomalies
Anomalies to be identified / effect of anomalies to be reduced / effect of variation in
data to be minimised;
Reject: idea of not recording anomalies / preventing anomalies
from occurring
A mean to be calculated;
Neutral: average
This document is licensed to Haggerston School - MB260045
Practice Paper 1 Maximum marks: 91
View detailed guidance on the conclusions you can draw from your students' performance in
these papers on the MERiT welcome page. Understand how your students compare with
others and target revision effectively by entering marks into MERiT.
1 (a) (i) fructose; 1
(ii) correctly drawn (OH group at bottom left); 1
(b) hydrolysis; 1
(c) (i) heat with Benedict’s solution (disqualify if HCl added);
orange / brown / brick red / green / yellow colour or precipitate; 2
(ii) biuret test / NaOH + CuSO4;
purple / violet / lilac / mauve; 2
(d) Starch (max 3)
1. Context of storage for starch, structure for cellulose
2. Helical/ spiral shape so compact;
3. Large (molecule)/insoluble so osmotically inactive;
Accept: does not affect water potential/ψ.
4. Branched so glucose is (easily) released for respiration;
Ignore: unbranched.
5. Large (molecule) so cannot leave cell/cross cell-surface membrane;
Cellulose (max 3)
5. Long, straight/unbranched chains of β glucose;
6. Joined by hydrogen bonding;
Note: references to ‘strong hydrogen bonds’ disqualifies this
mark point.
7. To form (micro/macro)fibrils;
8. Provides rigidity/strength; 5 max
[Total 12 marks]
Page 1
This document is licensed to Haggerston School - MB260045
, 2 (a) (i) break open cells / release cell contents; 1
(ii) keep pH the same / controls pH;
prevent change to / denaturing of proteins / enzymes; 2
(b) (i) 2
(supernatant) C (pellet) B; (pellet) A;
(ii) site of respiration which releases energy / ATP; 2
required for movement against concentration gradient;
ignore first point for thermodynamically incorrect statements
such as “making energy”.
[Total 7 marks]
3 (a) Bacteria killed; 1
Ignore: no growth or growth of bacteria prevented.
Accept: bacteria destroyed.
Accept: no living bacteria.
(b) Clear zone would be too large 1
OR Clear zones would overlap/merge
OR Could kill all bacteria (on the plate);
Must convey idea of too large.
(c) 1. (Same) size; 2 max
Accept: any measure of size e.g. thickness, area, diameter.
Ignore: ‘same shape’ as shape shown on the diagram.
2. (Same) material/absorbency;
3. In solution for same time period;
Ignore: reference to volume of disinfectant.
(d) Any number between 2.5 to 3.2 = two marks; 2
student has to use r squared to compare the areas of the cleared zones
Allow one mark for an incorrect answer but shows method of
calculating how many times more effective D is than B
e.g. 21/22 divided by 13/14
or 10.5/11 divided by 6.5/7
or 1.57/1.6/1.69/1.7.
[Total 6 marks]
4 (a) (i) 1.08; 1
Must be to 3 significant figures, as in the table
(ii) (Allows) 2
Accept: outliers instead of anomalies
Anomalies to be identified / effect of anomalies to be reduced / effect of variation in
data to be minimised;
Reject: idea of not recording anomalies / preventing anomalies
from occurring
A mean to be calculated;
Neutral: average
This document is licensed to Haggerston School - MB260045
