surname names
Number Number
May 2025 Edexcel: AS Level Biology B
8BI0/01 Paper 1 – Core Cellular Biology
and Microbiology – Merged Question
Paper & Mark Scheme
Morning (Time: 1 hour 30 minutes) Paper
B 🟐 🟐
Advanced Subsidiary
PAPER 1: Core Cellular Biology and Microbiology
Instructions
•• Use black ink or ball-point pen.
Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 80.
The marks for each question are shown in brackets
• Into question(s)
– use this as a guide as to how much time to spend on each question.
marked with an asterisk (*), marks will be awarded for your ability
structure your answer logically, showing how the points that you make are
related or follow on from each other where appropriate.
Advice
• Read each question carefully before you start to answer it.
• Try to answer every question.
• your answers if you have time at the end.
Check
Turn over
P78689A
©2025 Pearson Education Ltd.
Y:1/1/1/1/1/1/1/
, Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
DO NOT WRITE IN THIS AREA
1 Some carbohydrates are composed of three monosaccharides. These are
called trisaccharides.
Raffinose is a trisaccharide composed of glucose, galactose and fructose.
(a) Complete the diagram to show the structure of an alpha glucose molecule.
(2)
CH2OH
C O
H
C C
C C
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(b) Name the bond that joins monosaccharides together.
(1)
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
(c) The three monosaccharides present in raffinose each have a molecular mass
of 180.
The relative atomic mass of the element hydrogen is 1 and the relative atomic
mass of the element oxygen is 16.
Calculate the molecular mass of raffinose.
(1)
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Answer ..............................................................
(Total for Question 1 = 4 marks)
2
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, 2 During the S phase of the cell cycle, DNA is synthesised by
semi-conservative replication.
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The diagram shows part of a DNA molecule.
bases J and K
bases L and M
bond E
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bond D bond F
(a) (i) Name the base pairs labelled J and K, L and M.
(2)
J and K ............................................................................................................................. .. ........................................................................................................................ ....... .
L and M . . . . . . .. .. . .. .. . .. .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. . .. .. . .. .. . .. .. . .. .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. . .. .. . .. .. . . ............................................................................................................................. .
(1) Name the bonds labelled D, E and F.
(2)
Bond D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bond E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
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Bond F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
3
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, (2) Part of a DNA molecule consists of 840 bases. Of these, 136 are base J.
Calculate the percentage of bases that are M in this DNA molecule.
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Give your answer to two decimal places.
(1)
Answer ......................... %
(b) State what is meant by the term semi‑conservative replication.
(1)
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
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. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
(Total for Question 2 = 6 marks)
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4
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Number Number
May 2025 Edexcel: AS Level Biology B
8BI0/01 Paper 1 – Core Cellular Biology
and Microbiology – Merged Question
Paper & Mark Scheme
Morning (Time: 1 hour 30 minutes) Paper
B 🟐 🟐
Advanced Subsidiary
PAPER 1: Core Cellular Biology and Microbiology
Instructions
•• Use black ink or ball-point pen.
Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 80.
The marks for each question are shown in brackets
• Into question(s)
– use this as a guide as to how much time to spend on each question.
marked with an asterisk (*), marks will be awarded for your ability
structure your answer logically, showing how the points that you make are
related or follow on from each other where appropriate.
Advice
• Read each question carefully before you start to answer it.
• Try to answer every question.
• your answers if you have time at the end.
Check
Turn over
P78689A
©2025 Pearson Education Ltd.
Y:1/1/1/1/1/1/1/
, Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
DO NOT WRITE IN THIS AREA
1 Some carbohydrates are composed of three monosaccharides. These are
called trisaccharides.
Raffinose is a trisaccharide composed of glucose, galactose and fructose.
(a) Complete the diagram to show the structure of an alpha glucose molecule.
(2)
CH2OH
C O
H
C C
C C
DO NOT WRITE IN THIS AREA
(b) Name the bond that joins monosaccharides together.
(1)
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
(c) The three monosaccharides present in raffinose each have a molecular mass
of 180.
The relative atomic mass of the element hydrogen is 1 and the relative atomic
mass of the element oxygen is 16.
Calculate the molecular mass of raffinose.
(1)
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Answer ..............................................................
(Total for Question 1 = 4 marks)
2
■■■■
, 2 During the S phase of the cell cycle, DNA is synthesised by
semi-conservative replication.
DO NOT WRITE IN THIS AREA
The diagram shows part of a DNA molecule.
bases J and K
bases L and M
bond E
DO NOT WRITE IN THIS AREA
bond D bond F
(a) (i) Name the base pairs labelled J and K, L and M.
(2)
J and K ............................................................................................................................. .. ........................................................................................................................ ....... .
L and M . . . . . . .. .. . .. .. . .. .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. . .. .. . .. .. . .. .. . .. .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . .. . .. .. . .. .. . . ............................................................................................................................. .
(1) Name the bonds labelled D, E and F.
(2)
Bond D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bond E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
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Bond F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
3
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, (2) Part of a DNA molecule consists of 840 bases. Of these, 136 are base J.
Calculate the percentage of bases that are M in this DNA molecule.
DO NOT WRITE IN THIS AREA
Give your answer to two decimal places.
(1)
Answer ......................... %
(b) State what is meant by the term semi‑conservative replication.
(1)
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
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. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . . ......................
(Total for Question 2 = 6 marks)
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4
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