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Centre Number Candidate Number
Pearson Edexcel Level 3 GCE
Thursday 5 June 2025
Afternoon (Time: 2 hours) Paper
reference 9BN0/01
Biology A (Salters Nuffield)
Advanced
PAPER 1: The Natural Environment and Species
Survival
You must have: Total Marks
Calculator, HB pencil, ruler
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.
Show all your working out in calculations and include units where appropriate.
• Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 100.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
•• You may use a scientific calculator.
In questions marked with an asterisk (*), marks will be awarded for your ability to
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.
• Check your answers if you have time at the end. Turn over
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©2025 Pearson Education Ltd.
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, Answer ALL questions. Write your answers in the spaces provided.
Some questions must be answered with a cross in a box . If you change your mind about an
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answer, put a line through the box and then mark your new answer with a cross .
1 A sequence of changes takes place in the body of a mammal after death.
Forensic scientists can use this to help determine the time of death.
(a) State three changes that take place in the body of a mammal in the first 24 hours
after death.
(3)
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(b) Insects lay eggs on the body and their larvae feed on the dead tissue.
(i) Which of the following describes the sequence of organisms that colonise a
body after death?
(1)
A bacteria, beetles, flies
B bacteria, flies, beetles
C fungi, flies, bacteria
D beetles, flies, fungi
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, (ii) Explain the effect of an increase in temperature on the rate of decomposition.
(3)
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(Total for Question 1 = 7 marks)
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, 2 Most of the starch consumed by humans comes from the cereal crops: wheat,
maize and rice.
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Growth of cereal crops is reduced by drought and high temperatures.
(a) Which of the following describes the structure of starch?
(1)
A amino acids joined by glycosidic bonds
B amino acids joined by peptide bonds
C glucose molecules joined by ester bonds
D glucose molecules joined by glycosidic bonds
(b) Enset is a plant related to the banana plant. It is grown in Ethiopia in Africa, where
there is little rainfall and frequent droughts.
(Source: © Silarock/Shutterstock)
The fruit of the enset plant is the main source of starch for many people.
Enset plants are resistant to drought and high temperatures.
Explain why these plants may be a sustainable food source as global warming
brings about climate change.
(2)
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